To calculate how many milligrams will remain after 21 hours, we can use the formula for exponential decay. We are given that after 17 hours, 95 mg of the substance remains. Solving for the remaining amount after 21 hours gives us approximately 88.66 mg.
Explanation:To calculate how many milligrams will remain after 21 hours, we can use the formula for exponential decay:
R = Ro * e^(-kt)
Where:
R is the remaining amount after time tRo is the initial amountk is the decay constantt is the time periodWe are given that after 17 hours, 95 mg of the substance remains. Plugging these values into the formula, we can solve for k:
95 = 190 * e^(-17k)
Simplifying, we get:
e^(-17k) = 1/2
Taking the natural logarithm (ln) of both sides:
-17k = ln(1/2)
Solving for k, we find k = ln(1/2) / -17.
Now, we can use this value of k to find the remaining amount after 21 hours:
R = 190 * e^(-kt)
R = 190 * e^(-(ln(1/2) / -17) * 21)
Calculating this expression will give us the remaining amount after 21 hours, which is approximately 88.66 mg.
Which type of chemical protective clothing (cpc) protects the wearer against chemical vapors or gases?
What 3 things can molecules moving with kinetic energy do?
Explanation:
Kinetic energy is defined as the energy obtained by the molecules of a substance because of their motion.
Hence, when a substance or object is moving from its initial position then it means it has some amount of kinetic energy.
So, if molecules are moving then they have possessed kinetic energy and 3 things these molecules will do are as follows.
They will collide with the walls of a container or object in which they are placed.Also, molecules tend to collide with each other.And, they are able to pass or move through a pore.When a fluorine atom reacts with a chlorine atom, the bond that forms between them should be
ionic covalent.
nonpolar covalent.
ionic.
polar covalent.
Answer: Polar covalent
Explanation:
which element belongs to the alkali metal family
The Alkali metals includes
Lithium, Sodium Potassium Rubidium CaesiumFrancium. What are alkali metal?
The alkali metals are the metal which react with water forms alkalies that is strong bases capable of neutralizing acids.
The alkali metals have the high thermal and electrical conductivity, lustre, ductility, and malleability all are the characteristic of metals. Each alkali metal atom contains a single electron in its outermost shell. This valence electron is much more weakly bound than those in inner shells.
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Why haven't scientists been able to study atoms directly?
What mass in grams of ethylene oxide is needed to react with 18 g of water?
Complete the chart. (Remember to enter a 0 if necessary.)
Atomic Number: 3
1s:
2s:
2p:
3s:
3p:
4s:
3d:
4p:
5s:
Answer: The configuration of lithium element is [tex]1s^22s^12p^03s^03p^04s^03d^04p^05s^0[/tex]
Explanation:
Electronic configuration is defined as the representation of electrons around the nucleus of an atom.
Number of electrons in an atom is determined by the atomic number of that atom.
We are given:
Atomic number = 3
The element having atomic number '3' is lithium
The electronic configuration of lithium element is [tex]1s^22s^1[/tex]
Hence, the configuration of lithium element is [tex]1s^22s^12p^03s^03p^04s^03d^04p^05s^0[/tex]
If another scientist tests the substance using iodine, which macromolecule is the scientist testing for? question 27 options: carbohydrate lipid protein
What does a subscript indicate in a chemical formula?
Explanation:
A subscript is a number that is placed below an alphabet on the bottom right side.
For example, for [tex]H_{2}[/tex] molecule 2 is the subscript.
A subscript indicates the number of atoms present in a substance or molecule.
For example, in [tex]H_{2}SO_{4}[/tex] the subscripts indicate that there are two hydrogen atoms, one sulfur atom, and four oxygen atoms.
Read the clues. I have scales. My skin is dry.I breathe with lungs. I lay tough,leathery eggs. what vertebrate what am I ? A. reptile B. amphibian C. mammal D. bird help me plz ASAP
Which is generally true of enzymes in cells?
A) Enzymes allow reactions to proceed at body temperature.
B) Enzymes require co-enzymes to be effective.
C) Enzymes are organic compounds that the body needs in small amounts.
How much work (in j) is involved in a chemical reaction if the volume decreases from 5.00 to 1.26 l against a constant pressure of 0.857 atm?
The work done in the chemical reaction is 3.20 J.
Explanation:The work done in a chemical reaction can be calculated using the formula:
Work (W) = -P ∆V
Where P is the pressure and ∆V is the change in volume. In this case, the volume decreases from 5.00 to 1.26 L against a constant pressure of 0.857 atm. To calculate the work, we need to calculate the change in volume:
∆V = Vfinal - Vinitial = 1.26 L - 5.00 L = -3.74 L
Substituting the values into the formula, we have:
Work (W) = -P ∆V = -(0.857 atm) (-3.74 L) = 3.20 J
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The work done in the chemical reaction can be calculated using the formula W = P∆V, which gives the result as 292.1 Joules.
Explanation:Work done, especially in a process involving a gas, can be calculated when the pressure is constant and the volume changes. This is often referred to as pressure-volume work. In this particular case, we are given a process in a chemical reaction where the volume decreases from 5.00 to 1.26 L (a decrease of 3.74 L or 3.74 x 10^-3 m^3) against a constant pressure of 0.857 atm (which equals 0.857 x 1.01325 x 10^5 N/m^2). The formula to calculate work done is W = P∆V.
Inserting the given values into the formula, W = 0.857 x 1.01325 x 10^5 N/m^2 x 3.74 x 10^-3 m^3 which equals approximately 292.1 J (joules). Therefore the work involved in the chemical reaction is 292.1 J.
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The atomic number of sodium (na) is 11. how many electrons does a na atom have in its' valence shell?
a. 1
b. 2
c. 4
d. 8
What energy does satellite use
Which of the following measurements represents the most matter?
A. 0.033 kg
B. 0.33 hg
C. 330 g
D. 3300 cg
Answer: C) 330 g
Explanation: Since all the masses are given in different units, it's good to make all of them to have same unit. Let's say we convert all of them to grams.
A) kg stands for kilogram and 1 kg = 1000 g
So, [tex]0.033kg(\frac{1000g}{1kg})[/tex]
= 33 g
B) hg stands for hactogram and 1 hg = 100 g
So, [tex]0.33hg(\frac{100g}{1hg})[/tex]
= 33 g
C) 330 g
D) cg stands for centigram and 1 cg = 0.01 g
So, [tex]3300cg(\frac{0.01g}{1cg})[/tex]
= 33 g
Looking at all the choices, choice A, B and D represent equal amount of matter that is 33 g where as choice C represents 330 g of matter.
Hence, the correct choice is C) 330 g.
What does the space-filling model of a water molecule tell you about the relative size of the atoms?
238u undergoes radioactive decay to 234th. how many protons, electrons, and neutrons are gained or lost by the 238u atom during this process?
What are two methods of writing a balanced formula?
The two methods used to balance a chemical equation are :
(a) Inspection method.
(b) Algebraic method.
Methods to balance a chemical equationA chemical equation must satisfy the rules of conservation of mass and constant proportions.The rules state that the reactant and product sides of the formula must have the same amount of atoms of each element, the balancing technique is important.(A) Inspection method – In this method, we examine the equation and find the right balance.
Example- [tex]NaCl + BeF_2 = NaF + BeCl_2[/tex]In the above equation, the quantity of chlorine is not the same on both sides. In the product, there are two molecules of chlorine and in the reactant, there is only one. So to balance it, we will put 2 in the reactant.[tex]2NaCl + BeF_2 = NaF + BeCl_2[/tex]
Now, the quantity of nitrogen is two in the reactants but only one in the product. So we put 2 in front of the NaF in the product.[tex]2NaCl + BeF_2 = 2NaF + BeCl_2[/tex].
Now it is balanced.(B) Algebraic method
This approach of balancing chemical equations includes assigning algebraic variables to each species in the imbalanced chemical equation as stoichiometric coefficients.Thus, these are the two methods of balancing a chemical equation.
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Examine the equation.
C3H8(g)+5O2(g)→3CO2(g)+4H2O(l)
In the equation shown, what is the number 4 an example of?
reactant
chemical formula
coefficient
product
Answer:
Coefficient
Explanation:
We can explain this discarting options too. Now, let's write again the chemical equation;
C3H8(g)+5O2(g)→3CO2(g)+4H2O(l)
In a chemical equation, we have two sides. The left side we have the reactants of the reaction, these can be elements or compounds that reacts between each other, to produce another compound or substance. This compounds or elements are on the right side of the reaction. This side we have the products of the reaction of reactants.
Now, as in every situation of life, we need a balance of reactants and products, so, the only way to balance a chemical equation is by putting numbers behind every compound of the reactant and/or products to equal the number of atoms on each side. So if in the reactants we have 3 atoms of C, in the products we need to have the same 3 atoms.
Based on the above explanation, we can say that the number 4 is behind the H2O. This compound is on the side of products, but the number only, do not represent a product, so this option can be discarted.
A reactant cannot be either, cause it's not on the side of reactant.
Chemical formula, could be, if the number were as subscript, but it's not the case, and the chemical formula is composed of symbols.
Finally, as the number that we put behind the compounds work to balance the equation, the only function that these numbers have here, is to be coefficients of the reactions, and furthermore, it will work as mole.
So the correct option is the third one, Coefficient.
A tiny pencil mark just visible to the naked eye contains about 3 × 1017 atoms of carbon. what is the mass of this pencil mark in grams?
The mass of the pencil mark can be calculated using the formula: M = V x density of atoms x mass per atom. Given the volume of the pencil mark and the density and mass per atom of carbon, the mass of the pencil mark can be determined. The mass of the pencil mark is approximately 3.5 x 10^39 kg.
Explanation:The mass of the pencil mark can be calculated using the formula:
M = V x density of atoms x mass per atom
Given that the volume of the pencil mark is approximately 3 x 10-17 cm3 and the density and mass per atom of carbon are known, the mass of the pencil mark can be determined. Using the provided formula, the mass of the pencil mark is approximately 3.5 x 1039 kg.
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A syringe contains 0.65 moles of he gas that occupy 750.0 ml. what volume (in l) of gas will the syringe hold if 0.35 moles of ne is added? a syringe contains 0.65 moles of he gas that occupy 750.0 ml. what volume (in l) of gas will the syringe hold if 0.35 moles of ne is added? 1.9 l 4.9 l 2.1 l 0.87 l 1.2 l
Answer:
The correct answer from the given options is option 1.2 L.
Explanation:
Volume of the gases when 0.65 moles of gas are present = [tex]V_1=750 mL=0.750 L[/tex]
Volume of the gas when there 0.35 moles of gas are added= [tex]V_2[/tex]
[tex]n_1=0.65 moles,n_2=0.65+0.35 moles=0.10 moles[/tex]
According Avogadro law of gases:
[tex]\frac{V_1}{n_1}=\frac{V_2}{n_2}[/tex]
[tex]V_2=\frac{V_1\times n_2}{n_1}=1.15 L[/tex]
The closest answer from the given options is option 1.2 L.
From the explanation, we are given that:
The mole of gas [tex]{n_1}[/tex] = [tex] 0.65 moles[/tex]The volume it occupies [tex]{V_1}[/tex] = [tex] 750.0ml[/tex] = [tex]0.750L[/tex]Mole of Neon = [tex]0.35ml[/tex]The volume of gas it occupies when [tex]0.35moles[/tex] = [tex]{V_2}[/tex] (unknown)
Therefore we have:
[tex]{n_2}[/tex] = [tex]0.65[/tex] + [tex]0.35[/tex] = [tex]0.10moles[/tex] , [tex]{n_1}[/tex] = [tex]0.65moles[/tex]
Further ExplanationTo solve this question, we have to consider the Avogadro’s law, which state that "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules”
The law can be expressed as:
[tex]\frac{V_1}{n_1}=\frac{V_2}{n_2}[/tex]
[tex]V_2=\frac{V_1\times n_2}{n_1}[/tex]
[tex]V_2=\frac{0.750\times 0.10}{0.65}[/tex] = [tex]1.15L[/tex]
[tex]1.2L[/tex]
Therefore, the correct answer is 1.2L
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A syringe contains 0.65 moles of he gas that occupy 900.0 ml. what volume (in l) of gas will the syringe hold if 0.35 moles of ne is added? brainly.com/question/6860167A syringe contains 0.65 moles of he gas that occupy 750.0 ml. brainly.com/question/6442444KEYWORDS:
molessyringeconvertlitresavogradro's lawWhich of the following shows the path followed by nerve impulses in a reflex?
A.motor neurons → interneurons in brain → sensory neurons
B.sensory neurons → interneurons in brain → motor neurons
C.motor neurons → interneurons in spinal cord → sensory neurons
D.sensory neurons → interneurons in spinal cord → motor neurons
Sensory neurons, interneurons in spinal cord, motor neurons shows the path followed by nerve impulses in a reflex. Sensory neurons are the neurons that carry information from the environment externally to the central nervous system (CNS) mainly brain and motor neurons are those which carry information from CNS to other parts.
A human perceives something then by sensory neurons the information goes to CNS and that information is further passed by interneurons in spinal cord and is further passed by motor neurons from CNS to other parts to perform stimulus of perception.
An atom is determined to contain 34 protons, 36 electrons, and 34 neutrons. what are the mass number and charge of this atom or ion?
What are valence shell electrons
Compared To 620 nm photon, a 760 nm photon has ?
A 760 nm photon has less energy than a 620 nm photon because energy and wavelength of photons are inversely related. Longer wavelengths signify lower energy, so a 760 nm photon has less energy.
Explanation:Compared to a 620 nm photon, a 760 nm photon has lesser energy. This is because energy and wavelength of photons are inversely related, and thus, a longer wavelength (760 nm) signifies lower energy. Wavelength and energy are related by the equation E=hc/λ, where E is energy, h is Planck's constant, c is the speed of light, and λ is the wavelength. If the λ value increases, the E value decreases, assuming the values of h and c remain constant.
For example, a red photon (longer wavelength around 700 nm) carries less energy compared to a blue photon (shorter wavelength around 420 nm). This concept also applies to other types of electromagnetic radiation such as UV or infrared light, going beyond the visible light spectrum (380 to 720 nm). In essence, the longer the wavelength, the less energy the photon has, which is why a 760 nm photon has less energy than a 620 nm.
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Define monosaccharide disaccharide and polysaccharide give at least two examples of each. which of these is the
Monosaccharides, disaccharides, and polysaccharides are types of carbohydrates that consist of one, two, and many sugar molecules, respectively. Glucose and fructose are monosaccharides, sucrose and lactose are disaccharides, and starch and cellulose are polysaccharides.
Explanation:Monosaccharides are the simplest form of carbohydrates and consist of one sugar molecule. Examples include glucose and fructose. Disaccharides consist of two monosaccharide molecules bonded together. Sucrose (table sugar) and lactose (milk sugar) are examples of disaccharides. Polysaccharides are complex carbohydrates made up of many monosaccharides linked together. Starch and cellulose are examples of polysaccharides.
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The molar mass of sodium chloride is 58 g/mol. how many grams of sodium chloride are in 0.5 mol of sodium chloride?
Answer:
[tex]29 g. NaCl[/tex]
Explanation:
we know that it's molar mass is [tex]58 \frac{g}{mol}[/tex]
This means that 1 mol of sodium chloride contains 58g of sodium chloride; now How many grams of [tex]NaCl[/tex] are in 0.5 moles?
[tex]1 mol \longrightarrow 58g\\ 0.5 mol\longrightarrow x\\ x=\frac{0.5mol.58g}{1mol}=29g[/tex]
In 0.5 mol of NaCl there will be 29 g of sodium chloride
The nucleus of an atom is dense and positively charged. What was observed when positively charged particles were radiated onto a gold atom during Rutherford's experiment because of this?
Negative charges were concentrated at the center of the atom.
Particles that struck the center of the atom were repelled.
Particles that struck the edges of the atom were repelled.
Positive charges were distributed all over the atom.
Answer:
Particles that struck the center of the atom were repelled.
Explanation:
In 1911, New Zealand physicist Ernest Rutherford carried out an experiment in order to deepen his knowledge of the atomic model hitherto adopted, which was that of Thomson; in which the atom would be a sphere of positive, non-massive electrical charge, encrusted with (negative) electrons, so that its total electrical charge would be zero.
To carry out such an experiment he bombed a very thin gold leaf (thickness of approximately 10-4 mm), through a beam of alpha particles (α), coming from a sample of polonium. The polonium was inside a lead block, with an orifice, through which only the emissions of alpha particles would be allowed out.
In addition, lead plates with holes were placed in their centers, which would orient the beam towards the gold blade. And, finally, a bulkhead covered with zinc sulfide, which is a fluorescent substance, was placed behind the slide, where it was possible to visualize the path taken by the alpha particles.
At the end of this experiment, Rutherford noticed that most of the alpha particles passed through the slide, did not deflect or retreat. Some alpha particles deflected, and very few receded. In addition, the particles that reached the center of the atom were repelled.
Based on these data, Rutherford concluded that, contrary to what Dalton thought, the atom could not be massive. But in reality, much of the atom would be empty and it would contain a very small, dense and positive nucleus.
what is the name and the chemical symbol for the gas that caused the professor's voice to change - from the movie flubber
Answer:
Helium gas, symbol He
Explanation:
The gas that causes voice to change upon inhalation is helium which belongs to the inert gas/noble gas series in the periodic table. The chemical symbol is He.
When He gas is inhaled it fills up the vocal tract and replaces some of the air present in the cavity. Now, the density of He is much lower than that of air as a result the speed of sound as it passes through the vocal cavity increases which leads to a change in voice.
What is the difference between saturated and unsaturated fats answers?