Anton van Leeuwenhoek discovered tiny, single-celled organisms known as animalcules, now identified as bacteria, by examining dental plaque under his homemade powerful simple microscope.
Explanation:Anton van Leeuwenhoek, often referred to as the Father of Microbiology, made groundbreaking discoveries using a microscope he crafted himself. One of his most notable findings was when he examined the plaque from his own teeth. What he saw were tiny living organisms with a single cell, which he termed animalcules, now known as bacteria. His simple microscopes, through his superior lens-making skill, were almost as powerful as modern light microscopes. Leeuwenhoek's microscopes provided better resolution than other microscopes of his time, enabling him to observe human cells and bacteria closely. The discovery of these microorganisms laid the foundations of microbiology, a field that has evolved significantly since his time.
Anton van Leeuwenhoek discovered bacteria, which he called animalcules, with self-made microscopes almost as powerful as modern ones, marking a seminal event in microbiology.
Explanation:When Anton van Leeuwenhoek examined the plaque from his teeth under his homemade microscope, he discovered tiny living entities, which he named animalcules ("tiny animals"). These observed organisms are what we today refer to as bacteria
Leeuwenhoek's skill in crafting lenses led to the creation of a microscope that was nearly as powerful as our modern light microscopes, enabling him to be the first person to observe human cells and bacteria. His work marked a significant leap in the field of microbiology, confirming the existence of microscopic life which was previously only speculated.
A scientist is designing an investigation to study the impact of UV radiation present in high-altitude habitats on the population of mountain yellow-legged frog. What type population is most likely to be a control group for the study?
Answer:
I think its either C, Mountain frogs in a lab setting exposed to UV rays from a sun lamp or D, Mountain frogs in a lab setting with no UV ray exposure
Explanation:
EDIT: I searched up meaning of control group and got this,
"A control group in a scientific experiment is a group separated from the rest of the experiment, where the independent variable being tested cannot influence the results. This isolates the independent variable's effects on the experiment and can help rule out alternative explanations of the experimental results."
From this it would more likely to be D as the correct answer
passive transport involves movement of substances from?
An open box of bandages is on the floor.Bandages wrappers are found nearby,what chemical treatment do you use.
In the reaction ______ H2 + N2 ----> 2 NH3, what coefficient should be placed in front of H2 to balance the reaction?
a. 1
b. 2
c. 3
d. no coefficient is needed.
Your answer is 3.
3H2 + N2 → 2 NH3
How are molecules and compounds related??
Someone please help me with this one
Which are negative impacts that the internal combustion engine has had on society?
A.high power and health problems
B.noise pollution and health problems
C.efficient travel and noise pollution
D.efficient travel and high power
How much work (in J) is involved in a chemical reaction if the volume decreases from 5.00 to 1.48 L against a constant pressure of 0.819 atm?
A strong acid, HA, is added to water. Which statement about the solution is true?
It contains mostly hydroxide ions.
It contains almost no hydronium ions.
It contains little or no HA.
It contains a low amount of ions.
Answer:
The correct answer is:It contains little or no HA.
Explanation:
When a strong acid is added to water it dissociates into its constituent ion .
[tex]HA+H_2O\rightarrow H_3O^++A^-[/tex]
Actually the concentration of [tex]H^+[/tex] ions in water increases in comparison to hydroxide ions. And very little amount of HA will remain present associated in the solution.
A strong acid, HA, is added to water.The correct statement about solutions is: C. It contains little or no HA.
When a strong acid, HA, is added to water, it dissociates almost completely into hydronium ions (H₃O⁺) and its conjugate base (A⁻), leaving little or no undissociated HA.
Therefore, the solution primarily contains ions rather than the original acid molecules.When a strong acid, HA, is added to water, it ionizes almost completely. This means the acid dissociates fully into its ions, producing a high concentration of hydronium ions (H₃O⁺) and the conjugate base (A-). Therefore, the correct statement about the solution is: C. It contains little or no HA.A strong acid, by definition, yields nearly 100% of its hydrogen ions to water.This leads to a solution with a high concentration of H₃O⁺ ions and almost no undissociated HA molecules.
Correct question is: A strong acid, HA, is added to water. Which statement about the solution is true?
A. It contains mostly hydroxide ions.
B. It contains almost no hydronium ions.
C. It contains little or no HA.
D. It contains a low amount of ions.
If you increase the force of an object what happens to the acceleration
How many moles are in a 12.0 g sample of Fe2O3?
We know that Fe2O3 has a molar mass of 159.69 g / mol, therefore the number of moles of a 12 g sample is:
number of moles = 12 g / (159.69 g / mol)
number of moles = 0.075 mol
If the pattern of ions shown here for Galena is expanded in every direction, how many sulfide ions would surround each lead ion? How many lead ions would surround each sulfide ion?
If the pattern of ions in Galena is expanded, each lead ion would be surrounded by six sulfide ions, and each sulfide ion would be surrounded by six lead ions.
Galena (PbS) is a crystalline mineral with a specific repeating pattern of ions in its crystal lattice. Each lead (Pb) ion is surrounded by six sulfide (S²⁻) ions in a regular octahedral arrangement. In other words, if you expand this pattern in every direction, each lead ion would be surrounded by six sulfide ions.Conversely, each sulfide ion is also surrounded by six lead ions. This is because the arrangement of ions in a crystal lattice is such that each ion is surrounded by ions of the opposite charge to maintain overall electrical neutrality. In the case of galena, the lead ions and sulfide ions come together to form a highly structured crystal lattice where each ion is coordinated with six ions of the opposite charge.So, to summarize: Each lead ion in galena is surrounded by six sulfide ions. Each sulfide ion in galena is surrounded by six lead ions.For more such questions on ions
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1. Is mass conserved when 50 g of sugar undergoes a physical change? Use complete sentences to support your answer by explaining how this can be demonstrated.
2. During an investigation a scientist burned 48 g of magnesium strip. After the reaction the total mass of the product formed was found to be 80 g. Does the law of conservation of mass hold true in this case? Use complete sentences to justify your answer based on numerical calculations.
ACTUALLY answer the question please instead of posting stupid comments like on the last one
Answer:
Mass is still conserved even if it is melted or dissolved it is still conserved during and after the transformation.
Explanation:
I only have the answer to the first one. I did this on my school platform and still got it right.
Jonathan claims that since only humans can read, it must be an inherited trait, passed from human parents to their children. Is Jonathan correct in his claim?WHOEVER ANSWERS FIRST GETS BRAINLIEST ANSWER AND DONT GUESS
How many total atoms are in 2C6H12O6?
Calculate the osmotic pressure of a solution containing 24.6g of glycerin in 250ml of solution at 298K
Final answer:
The osmotic pressure of a solution containing 24.6g of glycerin in 250ml of solution at 298K is calculated using the formula for osmotic pressure and found to be 26.2 atm.
Explanation:
To calculate the osmotic pressure of a solution containing 24.6g of glycerin (C₃H₅(OH)₃) at 298K, we first need to find the molarity of the solution. Given that the molar mass of glycerin is approximately 92.09 g/mol, the moles of glycerin can be calculated as:
Moles of glycerin = 24.6 g / 92.09 g/mol = 0.267 moles
Since the solution volume is 250 mL, or 0.25 L, the molarity (M) of the solution is:
M = Moles of solute / Volume of solution (L) = 0.267 moles / 0.25 L = 1.068 M
The formula to calculate osmotic pressure (Π) is Π = iMRT, where:
i is the van't Hoff factor (For glycerin, i = 1 because it doesn’t dissociate in solution).
M is the molarity of the solution.
R is the ideal gas constant (0.0821 L.atm/mol.K).
T is the temperature in Kelvin.
Substituting the values into the formula gives:
Π = (1)(1.068 M)(0.0821 L.atm/mol.K)(298 K) = 26.2 atm
Therefore, the osmotic pressure of the solution is 26.2 atm.
In a chemical interaction 10 g of hydrogen chloride is added to 20 g of zinc to form 24 g of zinc chloride and a certain amount of hydrogen gas. What mass of hydrogen gas is expected to be formed? 6 g ,14 g ,34 g ,54 g
According to mass conservation law, the total mass of reactants that is 20 + 10 = 30g is equal to the total mass in the product side. 24 g of Zinc chloride is formed then to obtain a total mass of 30g 6 g of hydrogen gas is expected to be formed.
What is law of conservation of mass?Law of conservation of mass states that the mass is neither created nor destroyed. Thus total mass of the system is conserved. This law is thus similar to the law of conservation of energy.
According to this law the total mass in a reaction system also conserved which means the total mass of products formed will be equal to the total mass of reactants.
In the given chemical reaction, hydrogen chloride is 10 g and zinc is 20g, thus a total of 30 g is contained by the reactant side. The mass of zinc chloride formed is 24 g. One more product is formed there, i.e., hydrogen gas.
Thus total mass of zinc chloride and hydrogen gas is expected to be total mass of reactant side i.e.,30g Hence, mass of hydrogen expected to be formed is 30-24 g = 6 g.
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What type of reaction does the equation below represent? N2 + 3H2 —> 2NH3
a. synthesis
b. decomposition
c. single replacement
d. double replacement
The mass of the products after the reaction is 292 grams.Therefore, the mass of the reactants before the chemical reaction was_____
which sample of co2 has a definite shape and a definite volume
Write the symbolic notation of an isotope of an element having 8 protons, 8 electrons, and 9 neutrons
The element is identified exclusively by its number of protons. Atomic and mass numbers are included in isotopic notation. Oxygen isotope has an atomic number of 8 protons, 8 electrons, and 9 neutrons.
What is Isotopes?A chemical element's isotope is any of two or more species of atoms that share the same atomic number, position in the periodic table, and virtually identical chemical behavior.
But differ in atomic mass and physical characteristics. There are one or more isotopes for each chemical element.
Isotopes are forms of an element that have the same number of protons and electrons, but differing numbers of neutrons.
The many isotopes of an element have varying weights depending on how many neutrons there are in each one.
Therefore, Atomic and mass numbers are included in isotopic notation.
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Why would sand and water be an example of a heterogeneous mixture?
Select all that apply.
Chemical bonds are formed between the sand and water.
*The mixture does not have a uniform appearance.
*The mixture does not maintain a uniform composition.
The sand stays suspended in the water.
which of the following is an example of a physical change ?
A. A Piece of iron being heated until it melts
B. Silver jewelry tarnishing
C. A piece of wood burning
15 POINTS ASAP PLEASE!!
Which of these are found is the lymph?
A. Platelets
B. Red blood cells
C. Antibiotics
D. White blood cells
How is mass calculated given density and volume Volume divided by volume, Sum of volume and mass, Density multiplied by volume, Difference of volume and mass
C. Density multiplied by volume.
can you guys help me.
Fill in the blank
1. A(n) chemical _______________ is a description of a reaction using element symbols and chemical
formulas.
2.. _______________ are the starting substances in a chemical reaction.
3.. _______________ are the substances produced by a chemical reaction.
4. Mass is conserved in a chemical reaction because atoms are not _______________ or
_______________.
5.To show that mass is conserved, a chemical equation must be _______________, which means that
the number of each type of atoms must be the same on both sides of the equation.
6. Numbers in front of the symbols and formulas in an equation are called ____________________.
Study the following equation, then answer questions on the lines provided.
____ Al (s) + ____ CuCl (aq) → ____ AlCl3 (aq) + ____ Cu (s)
7. What are the products? ____________________________________________________
8. What are the reactants? ____________________________________________________
Can someone plz help me with these 5 questions!! Will give brainliest for right answers!! Thanks!!
1. The Hertzsprung-Russell diagram below shows how the brightness, surface temperature, and color of stars are related.stars would be
A. Barnard’s Star is less bright than the sun, has a surface temperature below 3,800 K, and is red.
B. Barnard’s Star is less bright than the sun, has a surface temperature above 3,800K, and is red.
C. Barnard’s Star is brighter than the sun, has a surface temperature below 5,300 K, and is yellow.
D. Barnard’s Star is brighter than the sun, has a surface temperature above 5,300 K, and is yellow.
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2. The Milky Way galaxy is described as a disk of stars orbiting a central point on the disk. Which of these best explains why people on Earth cannot see the entire shape of the Milky Way?
A. Earth is a part of this galaxy.
B. Many more stars exist outside the galaxy.
C. The stars in the center of the galaxy are extremely small.
D. The center of the galaxy consists of a dense cluster of stars.
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3. A student learns that the sun is classified as a medium-size star and that many stars are much bigger and brighter. However, the student observes that other stars look very dim, even through a telescope.Why do other stars look much dimmer than the sun?
A. The sun appears yellow, which is more visible than other colors.
B. The sun is much closer to Earth than other stars are.
C. Other stars are made up of different gases than the sun is.
D. As light from other stars travels through space, it gets reflected.
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4. The sun is a mid-sized, main sequence star. What stage is next in the life cycle of the sun?
A. red giant
B. black hole
C. white dwarf
D. neutron star
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5. In November 2013 an object orbiting the sun seemed to disappear behind the sun. When a satellite did not detect the object, astronomers thought that the object had been destroyed when it passed close to the sun. However, when another satellite detected a small, bright object with a fan-shaped tail, astronomers proposed that the object was not destroyed.What type of object were astronomers most likely observing?
A. A comet
B. An asteroid
C. A meteor
D. A nebula
Correct answer is A
A. Barnard’s Star is less bright than the sun, has a surface temperature below 3,800 K, and is red.
Explanation:The below Hertzsprung Russell diagram abbreviated H–R diagram, or HRD is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.
Answer 2:Correct option is A
A. Earth is a part of this galaxy.
Explanation:The Milky Way galaxy is described as a disk of stars orbiting a central point on the disk. The Milky Way is the galaxy that contains our Solar System. The word "milky" is derived from the galaxy's appearance from Earth: a band of light seen in the night sky formed from stars that cannot be individually detected by the naked eye.
Answer 3:Option B is correct.
B. The sun is much closer to Earth than other stars are.
Explanation:Sun is classified as a medium-size star and that many stars are much bigger and brighter because Sun is far more near to the earth as compared to other stars. Other stars are thousands of galaxy years far from earth.
Answer 4:Option A is correct.
A. red giant
Explanation:Sun is a sphere-shaped star made up of hot plasma, with an internal convective motion that creates a magnetic field via a dynamic process. It is the most important source of energy for life on Earth.
Answer 5:Option A is correct.
A. A comet
Explanation:In November 2013 an object orbiting the sun seemed to disappear behind the sun. When a satellite did not detect the object, astronomers thought that the object had been destroyed when it passed close to the sun. However, when another satellite detected a small, bright object with a fan-shaped tail, astronomers proposed that the object was not destroyed. After that it was concluded as a comet.
A comet is an icy tiny Solar System body. When it passes near the sun it gets warmer This produces an apparent atmosphere or coma, and sometimes also leave a tail.
Solar system consists of the Sun and other that are bound to it by gravity
and a the same time orbit around it.
The following are answers to the questions :
Barnard’s Star is less bright than the sun, has a surface temperature below 3,800 K, and is red.Earth is a part of this galaxy best explains why people on Earth cannot see the entire shape of the Milky Way.Other stars look much dimmer than the sun because the sun is much closer to Earth than other stars are.Red giant stage is next in the life cycle of the sun.Comet is the type of object were astronomers most likely observing.Read more about Solar system here https://brainly.com/question/24721218
Both gold (Au) and oxygen (O) are listed on the periodic table. What do both Gold and Oxygen have in common?
Choose all the answers that apply.
Cell waste is removed from the body by _____.
- breathing
- sweating
- going to the bathroom
- eating
A powdered drink mix is stirred into a glass of water to form a solution. If any more is added it will not dissolve
How many moles of MgSiO3 are in 199 g of the compound?
There are 1.98 moles of MgSiO₃ in 199 g of the compound, so one needs to use the molar mass of MgSiO₃, which is the sum of the atomic masses of its constituent elements.
What are moles of compound?The atomic mass of Mg is 24.31 g/mol, the atomic mass of Si is 28.09 g/mol, and the atomic mass of O is 16.00 g/mol. Therefore, the molar mass of MgSiO₃ is:
molar mass of MgSiO₃ = (1 x atomic mass of Mg) + (1 x atomic mass of Si) + (3 x atomic mass of O)
molar mass of MgSiO₃ = (1 x 24.31 g/mol) + (1 x 28.09 g/mol) + (3 x 16.00 g/mol)
molar mass of MgSiO3 = 100.39 g/mol
moles = mass/molar mass
To calculate the number of moles of MgSiO₃ in 199 g of the compound:
moles of MgSiO₃ = 199 g / 100.39 g/mol
moles of MgSiO₃ = 1.98 mol
Hence, there are 1.98 moles of MgSiO₃ in 199 g of the compound, so one needs to use the molar mass of MgSiO₃, which is the sum of the atomic masses of its constituent elements.
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