2016 the warmest year on record, but eight of the twelve months that make up the year from January through September, with the exception of June were the warmest on record for those respective months. This is evidence showing how the climate has changed
Answer:
Climate change is caused when fuel is burned. This leads to excess carbon dioxide into the air. Scientists know that climate change is happening when:
the temperature is getting hottersea levels are risingHope this helps and have a good day!
Which of the following statements are true about metallic bonds?
A. They hold together ionic bonds.
B. They bond a metal to a nonmetal.
C. They bond identical atoms together.
D. They hold together atoms with different electronegative.
Answer:
B. They bond identical atoms together
Explanation:
Metallic Bond: This is the bond that exists among the atoms of the metal. This is a type of electrostatic attraction between conduction electrons of metallic atom and their positively charged metal ions.
(figure attached)
Example:
Copper is a metallic element and its atoms consist of metallic bond among their selves.
Options A, B, D are not correct as all states for a kind of ionic bond formation.
Ionic bond:
It form by the complete transfer of electron from one atom to other
It is formed among two atoms of different electronegativities.
Also metals are electro-positive and non -metals are electro-negative so they form ionic bond.
Example is NaCl where sodium is a metal and Chloride is non-metal and they from ionic bond.
Answer:
C. They bond identical atoms together.
Explanation:
Select the correct answer.
What does the kinetic theory state about the relationship between the speed and temperature of gas molecules?
A.As the temperature increases, the speed of gas molecules remains constant.
B.As the temperature increases, the speed of gas molecules decreases.
C.As the temperature increases, the speed of gas molecules increases.
D. As the speed of gas molecules increases, the temperature becomes constant
E.As the temperature decreases, the speed of gas molecules increases.
Answer:
C. As the temperature increases, the speed of gas molecules increases
Answer:
C. As the temperature increases, the speed of gas molecules increases.
Explanation:
Kinetic Molecular Theory states that gas particles are in constant motion and exhibit perfectly elastic collisions. Kinetic Molecular Theory can be used to explain both Charles’ and Boyle’s Laws. The average kinetic energy of a collection of gas particles is directly proportional to absolute temperature only.The following are the basic assumptions of the Kinetic Molecular Theory:
The volume occupied by the individual particles of a gas is negligible compared to the volume of the gas itself. The particles of an ideal gas exert no attractive forces on each other or on their surroundings. Gas particles are in a constant state of random motion and move in straight lines until they collide with another body. The collisions exhibited by gas particles are completely elastic; when two molecules collide, total kinetic energy is conserved. The average kinetic energy of gas molecules is directly proportional to absolute temperature only; this implies that all molecular motion ceases if the temperature is reduced to absolute zero.So, the right choice is:
C. As the temperature increases, the speed of gas molecules increases.
I have two solutions. In the first solution, 1.0 moles of sodium chloride is dissolved to make 1.0 liters of solution. In the second one, 1.0 moles of sodium chloride is added to 1.0 liters of water. is the molarity of each solution the same?
The molarity of both solutions is the same, equaling to approximately 1.0 M (mol/L), because molarity is determined by the number of moles of solute per liter of solution, not just the solvent.
Explanation:Yes, the molarity of both solutions would indeed be the same. Molarity is defined as the number of moles of solute per liter of solution. In your first solution, you dissolved 1.0 moles of NaCl in a total of 1.0 liter of solution. In your second situation, you added 1.0 moles of NaCl to 1.0 liters of water, assuming it does not change the volume substantially, the total volume of the solution is also about 1.0 liters. Thus, the molarity, in both cases, would be approximately 1.0 M (mol/L). It's important to remember that molarity takes into consideration the entire volume of the solution, not just the solvent.
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While both solutions have the same amount of sodium chloride, the process of preparation leads to different volumes of the final solution which influences the molarity. Thus, the molarities of the two solutions are different with the first one being more concentrated.
Explanation:The molarity of a solution is calculated by dividing the number of moles of solute by the volume of the solution in liters.
In the first solution, 1.0 mole of sodium chloride (NaCl) is dissolved to make 1.0 liters of solution, hence its molarity is 1.0 moles/liter.
In the second solution, 1.0 moles of NaCl is added to 1.0 liters of water; however, when sodium chloride is added, the volume of the solution increases, so the resulting volume of the solution is greater than 1.0 liter which ultimately lessens the molarity of the solution.
Therefore, the molarity of the first solution is greater than the molarity of the second solution despite having the same amount of sodium chloride.
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Use the standard enthalpies of formation for the reactants and products to solve for the ΔHrxn for the following reaction
Ca(s)+ 2H20(l) → Ca(OH)2(s)+H2(g)
∆Hrxn=
The reaction is =
Answer:
- 386.6 kJ/mol.
Explanation:
To solve this problem, we can use Hess's Law:ΔHrxn = ΣΔHf(products) - ΣΔHf(reactants)
For this reaction: Ca(s)+ 2H₂O(l) → Ca(OH)₂(s) + H₂(g),
∴ ΔHrxn = ΣΔHf(products) - ΣΔHf(reactants) = [ΔHf(Ca(OH)₂(s)) + ΔHf(H₂)(g)] - [ΔHf(Ca)(s) + 2*ΔHf(H₂O)(l)].
knowing that:ΔHf(Ca(OH)₂(s)) = - 985.2 kJ/mol, ΔHf(H₂)(g) = 0.0 kJ/mol, ΔHf(Ca)(s) = 0.0 kJ/mol, ΔHf(H₂O)(l) = - 285.8 kJ/mol.
∴ ΔHrxn = ΣΔHf(products) - ΣΔHf(reactants) = [ΔHf(Ca(OH)₂(s)) + ΔHf(H₂)(g)] - [ΔHf(Ca)(s) + 2*ΔHf(H₂O)(l)] = [(- 985.2 kJ/mol) + (0.0 kJ/mol)] - [(0.0 kJ/mol) + 2*(- 285.8 kJ/mol)] = - 386.6 kJ/mol.
Which of these is an example of a chemical change?
Deflating a rubber balloon
Combining rubber with sulfur
Stretching an elastic rubber band
Erasing pencil marks from a page
Answer: combining rubber with sulphur
Explanation:
Chemical change is the change in which chemical composition of the substance changes by rearrangement of atoms.
Physical change is a change in which only the physical properties such as size, shape etc change and there is no rearrangement of atoms.
1. Deflating a rubber balloon only decreases the size of balloon and hence is a physical change.
2. Combining rubber with sulphur is vulcanisation in which sulphur forms bonds with rubber and thus is a chemical change.
3. Stretching an elastic rubber band only changes the shape and hence is a physical change.
4. Erasing pencil marks from a page does not involve any rearrangement of atoms and thus is a physical change.
Today's lunch is related to your overall diet in the same way that today's weather is related to ______________.
A. Precipitation
B. Climate
C. The atmosphere
D. The water cycle
Answer:
B . Climate
Explanation:
lunch is temporary to diet is long lasting so , weather is temporary and climate is long lasting
Today's weather is related to climate, where weather indicates the short-term atmospheric conditions and climate represents long-term patterns, similar to a single meal in relation to an overall diet.So,option B is correct.
Today's lunch is related to your overall diet in the same way that today's weather is related to climate. While the individual meal you eat today is a single occurrence that contributes to your dietary pattern over time, today's weather refers to the specific atmospheric conditions present at a given moment. In contrast, the climate refers to the long-term, predictable atmospheric conditions of a specific area. Weather can be considered the short-term variation, just like one meal is to an overall diet, while climate represents the long-term trends in weather patterns, similar to how a diet represents long-term nutritional habits.
Which of the following is an example of an environmental problem caused by chemicals
Answer:
A
Explanation:
All of the other options are ways that could help the environment from the chemicals, but if they just continue to use the chemicals then it would hurt the environment
Final answer:
Environmental problems caused by chemicals often involve contamination of ecosystems and food supplies, with substances like DDT and PCBs serving as examples of harmful environmental alterations.
Explanation:
An environmental problem caused by chemicals can manifest in various forms, including contamination of ecosystems and food supplies with harmful chemical agents. For example, chemicals such as DDT and its breakdown product DDE, or industrial chemicals like polychlorinated biphenyl (PCB), have contaminated food sources and adversely affected the environment. Persistent organic pollutants, introduced into the environment without a natural occurrence or in unnatural ratios, are known to cause environmental alterations, with their full scale of effects being difficult to calculate. This kind of problem highlights the significant role of chemists and chemical engineers in addressing the challenges posed by these substances, fostering environmentally beneficial chemistry and responsible manufacturing practices.
4Al + 3O2 → 2Al2O3
In this chemical reaction, how many grams of Al2O3 will be produced if 375 grams of Al react completely? Express your answer to three significant figures.
The mass of [tex]\( \text{Al}_2\text{O}_3 \)[/tex] produced is approximately [tex]\( 709 \text{ g} \).[/tex]
To determine the mass of [tex]\( \text{Al}_2\text{O}_3 \)[/tex] produced when 375 grams of [tex]\( \text{Al} \)[/tex] react completely, follow these steps:
Given Reaction:
[tex]\[ 4 \text{Al} + 3 \text{O}_2 \rightarrow 2 \text{Al}_2\text{O}_3 \][/tex]
Steps:
1. Calculate the molar mass of [tex]\( \text{Al} \) and \( \text{Al}_2\text{O}_3 \):[/tex]
Molar mass of Al aluminum: [tex]\( 26.98 \text{ g/mol} \)[/tex]
Molar mass of [tex]\( \text{Al}_2\text{O}_3 \)[/tex] aluminum oxide:
[tex]\[\text{Molar mass of } \text{Al}_2\text{O}_3 = (2 \times 26.98 \text{ g/mol}) + (3 \times 16.00 \text{ g/mol}) = 53.96 \text{ g/mol} + 48.00 \text{ g/mol} = 101.96 \text{ g/mol}\][/tex]
2. Convert the mass of [tex]\( \text{Al} \)[/tex] to moles:
[tex]\[\text{Moles of Al} = \frac{\text{mass of Al}}{\text{molar mass of Al}} = \frac{375 \text{ g}}{26.98 \text{ g/mol}} \approx 13.91 \text{ mol}\][/tex]
3. Use the stoichiometry of the reaction to find the moles of [tex]\( \text{Al}_2\text{O}_3 \)[/tex] produced:
According to the balanced equation, 4 moles of Al produce 2 moles of[tex]\( \text{Al}_2\text{O}_3 \)[/tex]. So:
[tex]\[\text{Moles of } \text{Al}_2\text{O}_3 = \left(\frac{2 \text{ moles } \text{Al}_2\text{O}_3}{4 \text{ moles Al}}\right) \times 13.91 \text{ mol} = 6.95 \text{ mol}\][/tex]
4. Convert the moles of [tex]\( \text{Al}_2\text{O}_3 \)[/tex] to grams:
[tex]\[\text{Mass of } \text{Al}_2\text{O}_3 = \text{moles of } \text{Al}_2\text{O}_3 \times \text{molar mass of } \text{Al}_2\text{O}_3\][/tex]
[tex]\[\text{Mass of } \text{Al}_2\text{O}_3 = 6.95 \text{ mol} \times 101.96 \text{ g/mol} \approx 708.7 \text{ g}\][/tex]
What is data that is not directly collected or observed by the scientist called?
.
A. Research data
B. Adjunct data
C. Secondary data
D. Derivative data
Answer: C. Secondary data
Explanation:
It means that the data that was collected by someone else that is not the scientist, it may include censuses, surveys, data bases or other sort of information. Such data could be collected by different private companies, from organizational records to government departments, as they often collect data for other research purposes and the information is available to be used for other scientific purposes.
A data that is not directly collected or observed by the scientist is called: C. Secondary data.
What is data?Data can be defined as a representation of instructions or factual information in a formalized manner, especially as a series of binary digits (bits) or samples that are used by scientist in an experiment or research.
Generally, there are two (2) main types of data and these include:
Primary dataSecondary dataIn Science, a secondary data refers to a type of data that isn't directly collected or observed by the scientist but from a primary source.
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Match each decimal number to the correct scientific notation. 30,700 0.000307 0.00000307 3,070,000 3.07 × 10-6 arrowRight 3.07 × 106 arrowRight 3.07 × 10-4 arrowRight 3.07 × 104 arrowRight
Answer:
3.07 × 10^4=30,700
3.07 × 10^-4=0.000307
3.07 × 10^-6=0.00000307
3.07 × 10^6=3,070,000
Explanation:
Answer:
30,700 = [tex]3.07\times 10^4[/tex]0.000307 =[tex]3.07\times 10^{-4}[/tex]0.00000307 = [tex]3.07\times 10^{-6}[/tex]3,070,000 = [tex]3.07\times 10^6[/tex]Explanation:
Scientific notation: It is the representation of expressing the numbers which are too big or too small by representing them in decimal form with one digit before the decimal point times 10 raise to the power.
For example : 6,000,000 is written as [tex]6.0\times 10^6[/tex]
30,700 = [tex]\frac{10^4}{10^4}30,700=3.07\times 10^4[/tex]0.000307 =[tex]\frac{000307}{10^6}= 3.07\times 10^{-4}[/tex]0.00000307 = [tex]\frac{00000307}{10^8}= 3.07\times 10^{-6}[/tex]3,070,000 = [tex]\frac{10^6}{10^6 }\times 3,070,000=3.07\times 10^6[/tex]HELP ASAP! GIVING BRAINLIEST!!
How could you give a pendulum more energy?
Answer:
Explanation:
In a simple pendulum with no friction, mechanical energy is conserved. Total mechanical energy is a combination of kinetic energy and gravitational potential energy. As the pendulum swings back and forth, there is a constant exchange between kinetic energy and gravitational potential energy
as you increase the temperature of a solute it's solubility
What specific characteristics or characteristics contribute to the attraction between Earth and the moon
Answer:
Gravity and Mass.
Explanation:
The Earth has more mass than the moon and therefore a higher force of gravity. Because the Earth has a higher mass and force of gravity the moon is attracted to it.
how do adaptations help an organism to reduce competition for food and other resources?
the niche of an organism is largely based on the evolution of an organism's physiology, behavior, and morphology
There are four time zones in the continental United States.
True
False
Answer:
True
Explanation:
There are four time zones in the continental United States: Eastern, Central, Mountain and Pacific.
There are four time zones in the continental United States. Hence, option A is correct.
What is continental?A continent is a large continuous mass of land conventionally regarded as a collective region.
There are actually six time zones in the USA.
The four main ones are Eastern, Central, Mountain, and Pacific Standard Time.
Hence, option A is correct.
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Which is an intensive property of a substance?
Odensity
O volume
O length
O mass
Answer:
density
Explanation
3-ethyl-2-methyl-2-pentene
What is the molarity of a solution made by mixing 3.50 g of potassium chromate in enough water to make 100.00 ml of this solution?
Answer:
.18 M
Explanation:
1st
The molarity of an aqueous solution (a solution that has water as the solvent) can be found just by remember this one formula = [tex]\frac{mol}{liters}[/tex].
[moles of solute / volume of solution in L]
So, what do we have? From a glance we have the number of solute (Potassium Chromate), that tells us that we need to convert that value that is in grams (g) into...Moles or (mol), we can do that like this
[tex]\frac{3.50 g}{ } \frac{1 mol}{194.19 g}[/tex]
After we cross multiply 3.50 times 1 and then divide by 194.19 - we get this value ⇒ .018 mol (the g cancels, and we keep mol)
(We get the 194.19 from adding up the molecular weight of Potassium Chromate, which is about 194.19 g/mol. In the above equation though, we flipped this, so that 1 mol is in the numerator and the 194.19 is in the denominator; this helps us convert the 3.50 g to moles).
2nd
Now, we just have to remember that 1 liter = 1000 ml. Because its easier for us to use a L instead of "ml" in the molarity formula. So...
100.00 ml = .1 L ....
(because [tex]\frac{100 ml}{ } \frac{1 L}{1000 ml} = .1L[/tex]
Finally, we just add our (.018 mol and .1 L) into one nice equation (plug the numbers we converted to back in)
[tex]\frac{.018 mol}{.1L} = .18 M[/tex]
Is it clear now?
f a hypothesis can stand the test of repeated examination, it can become a _____.
theory
Answer: Accepted Theory
Explanation: A scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results. Where possible, theories are tested under controlled conditions in an experiment.
Which statement about astrology is not true? the positions of the planets at the time of birth have influence on a persons life
Answer:
The positions of the planets at the time of birth have influence on a person's life
Can some one help me with science . I am having a difficult time .
Kilometer - km - 1,000
Hectameter - hm - 100
Decameter - dam - 10
Millimeter - mm - 0.001
The table provides clear prefix rules.
The prefixes can be used for most (if not all) units such as grams (kg,mg...).
Hello there i hope you are having a good day :) Answer :
Prefix with the base unit meter : Symbol : Number of meters :
. (kilometre) (Km) = 1000 m
. (Hectometre) (HM) = 100 m
. (Decameter) (Dam) = 10 meters
. (Millimetre) (mm) = 0.001 meters
Hopefully this help you :)
Which area should have the lowest temperatures?
A. 1
B.2
C.3
D.4
Answer:
A. 1
Explanation:
The higher you get in the atmosphere the cooler the temperature will be. The reason it's actually colder is because, as you go up in the atmosphere, the Earth's atmosphere feels less pressure the higher up you go. So as the gas in the atmosphere rises it feels less pressure, which makes it expand.
Hope this Help :)
Please mark brainliest :D
Answer:
The first one is right :)
Explanation:
I got it right on Plato.
the three factors that determine the characteristics of a solution are
Answer:
Instrinsic Solubility, Temperature, and Sample Size.
Fill in the coefficients that will balance the following reaction:
a0Ca + a1CO2 + a2O2 → a3CaCO3
Answer:
Explanation:
aCa + bCO₂ + cO₂ → dCaCO₃
Chemical reactions obey the law of conservation of matter. The law states that "matter is neither created nor destroyed in the course of a chemical reaction". From this, we can deduce that the total mass of the products and reactants are equal.
To balance a chemical reaction, we can do so by inspecting the atoms/compounds involved and putting the appropriate coefficients at the back of the reactants and products. For equations in which inspection might not easily work, we can use a mathematical approach.
By inspecting the reaction above, we can easily balance it
Using the mathematical approach:
The coefficients are a,b,c and d. They are needed to conserve the atoms. So:
For Conservation of Ca: a = d (i)
C: b = d (ii)
O: 2b + 2c = 3d (iii)
if we assume that a = 1, then d = 1
b = 1
from (iii): 2c = 3d -2b
2c = 3- (2 X 1)
2c = 1
c = [tex]\frac{1}{2}[/tex]
Therefore we have a = 1
c = [tex]\frac{1}{2}[/tex]
b = 1
d = 1
aCa + bCO₂ + cO₂ → dCaCO₃
Ca + CO₂ + [tex]\frac{1}{2}[/tex]O₂ → CaCO₃
What is the total number of calories
of heat that must be absorbed to
change the temperature of
100 grams of H20 from 25°C to
30°C? (specific heat for H20 = 1
cal/g)
A 100
B 500
C 2,500
D 3,000
Answer:
D
Explanation:
40 POINTS.will give brainliest happily if helped ASAP
1.
Which of the following muscles are attached to a bone?
Bladder muscles
Cardiac muscles
Skeletal muscles
Stomach muscles
2.
What is the main function of the endocrine system?
To control body activities through the release of chemicals
To help in body movements and maintaining posture
To produce new individuals through fertilization
To exchange gases like oxygen across the body
3.
Which of the following microorganisms is most likely to get its main source of nutrition from a host?
Bacteria
Parasite
T-cell
Virus
Answer:
1 is Cardiac muscles
2 is To control body activities through the release of chemicals
3 is Bacteria
Explanation:
Answer:
1. Skeletal Muscles
2. To control body activities through the release of chemicals
3. Parasite
What is the scientific notation of 696,000?
Hello There!
Your answer is In Image Provided.
How many grams of hydrogen are necessary to react with 2.85 mol CO
CO+2 H2=CH3OH
2.85 mol Co x (2mol H2/1 mol Co)=5.70 mol just concert to grams
5.70 mol H2 x (2 g H2/1 mol H2) =11.40 grams of H2
To react with 2.85 moles of CO, 11.4912 grams of hydrogen gas (H₂) are necessary based on the balanced equation 2 H₂ + CO → CH₃OH.
Explanation:To determine how many grams of hydrogen are necessary to react with 2.85 mol of CO, we need to refer to the balanced chemical reaction equation that hydrogen and CO might participate in. One such reaction is the synthesis of methanol:
2 H₂ + CO → CH₃OH
According to this equation, 2 moles of hydrogen gas (H₂) react with 1 mole of carbon monoxide (CO) to produce methanol (CH₃OH). Therefore, to react with 2.85 moles of CO, we would need 5.70 moles of hydrogen gas (2 x 2.85 moles of CO). To convert moles of hydrogen to grams, we multiply by the molar mass of hydrogen (approximately 2.016 g/mol for H₂).
5.70 moles H₂ x 2.016 g/mol = 11.4912 g of H₂
Thus, 11.4912 grams of hydrogen are necessary to react with 2.85 moles of CO.
2 Points
What kind of bond would many atoms of the same metal make?
Answer:
A metallic bond
Explanation:
Which describes energy changes during nuclear fission?
PLEASE EXPLAIN HOW YOU GOT YOUR ANSWER!!!!
A very large amount of energy is produced from a tremendous mass.
A very large amount of energy is produced from a series of chemical reactions.
A very large amount of energy is produced from a very small mass.
Answer:
A very large amount of energy is produced from a very small mass
Explanation:
Nuclear energy is produced either by fusion or fission. The former is the fusion of lighter atoms into heavier elements while the latter is the splitting of a heavier atom into lighter atoms. Both produce tremendous amounts of energy. Fusion, causes compaction of mass while fission reduces it. Fusion does not produce radioactive particles while fission does (alpha and beta particles and neutrons).
Energy changes during nuclear fission involve the conversion of a very small amount of mass into a large amount of energy, much more than is produced in chemical reactions like burning coal.
Nuclear fission is a process where the nucleus of an atom, typically a heavy element like uranium-235, is split into smaller, lighter nuclei. The correct description of energy changes during nuclear fission is: a very large amount of energy is produced from a very small mass. This is due to the relationship between mass and energy as described by Einstein's mass-energy equivalence formula, E=mc2. When a mole of uranium-235 undergoes fission, there is a small decrease in the total mass of the products compared to the original mass (about 0.2 grams). According to the formula, this 'lost' mass is converted into a vast amount of energy, approximately 1.8 × 1010 kJ per mole. This energy release in nuclear fission reactions far exceeds the energy produced in chemical reactions, such as the burning of coal.