Answer:
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Explanation:
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The half-life of a radioactive isotope is 2.4 minutes. If you started with 100.0 grams, how many grams would be left after 7.2 minutes has elapsed? Explain how you arrived at your answer.
Answer:
12.5grams would remain after time has elapsed
Two gas jars are connected to each other, but they are separated by a closed valve. One gas jar contains oxygen, and the other contains hydrogen. What will happen when the valve is opened?
Answer Choices:
A. Oxygen and hydrogen molecules will mix because of random movement of their molecules.
B. Oxygen and hydrogen molecules will remain in separate jars because of different partial pressures.
C. Oxygen and hydrogen molecules will remain in separate jars because of different rates of expansion.
D. Oxygen and hydrogen molecules will mix because the molecules have a much lower volume than the volume of the jars.
When the valve is opened, oxygen and hydrogen molecules will mix because of random movement of their molecules.
What is diffusion?
Diffusion involves the movement of gas molecules from one region where they are in higher concentration to another region where they are in lower concentration.
When the valve is opened, oxygen and hydrogen molecules will mix because of random movement of their molecules.
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Answer:
Oxygen and hydrogen molecules will mix because of random movement of their molecules.
Explanation:
Which of the following elements are most likely to form an ionic bond
K and Ca
S and Cl
K and Cl
C and O
Answer:
K (Potassium) and Cl (Chlorine)
Explanation:
Ionic bonds are formed with metals and nonmetals
Covalent bonds are formed only with nonmetals
Calcium and potassium are both metals
Sulfur and Chlorine are both nonmetals so they don't form ionic bonds
Carbon and Oxygen are both nonmetals so they don't form ionic bonds
Consider the following reaction:
Mg + 2H2O Mg(OH)2 + H2 ΔH = -353 kJ
This reaction is
A.
exothermic because heat is released.
B.
endothermic because heat is released.
C.
endothermic because heat is absorbed.
D.
exothermic because heat is absorbed.
Answer:
A
Explanation:
I think it's the answer
Look at the graph. Which part of the line shows a time
when the object was not moving?
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Answer:
We have the atoms, and we have the molar mass of Vanadium (listed in the periodic table) which should be 50.94g/mol.
The first step is to convert the 4.18 x 10^23 atoms into moles by dividing the atoms by Avogadro's number (6.02 x 10^23)
(4.18 x 10^23)/(6.02 x 10^23) = 0.694 moles
Now we know that moles is equal to the mass divided by the molar mass. So now that we have the moles and the molar mass of Vanadium, we can rearrange the equation to find mass. Once you have rearranged it, you have to multiply the moles by the molar mass.
So 0.694 moles x 50.94g/mol = 35.35g of V
good and bad effects of changes in materials in the environment
Answer:
Composting, recycling, technological development, water cycle and photosynthesis are changes that have good effects. Some changes have bad effect like pollution and destruction of habitat and lose of lives.
Explanation:
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how many grams are in 4.5 x 10^22 molecules of water
Answer:
1.35 g
Explanation:
water is h2o, so the molar mass is 1.01x2+16.00=18.02. divide 4.5 x 10^22 by 6.022 x 10^23 to get 7.5 x 10^-2 (2 sig figs). 18.02 x 7.5 x 10^-2 is 1.35 g
Millikan determined the electron's ______ .
Answer
In 1909, Robert Millikan and Harvey Fletcher conducted the oil drop experiment to determine the charge of an electron. ... Using the known electric field and the values of gravity and mass, Millikan and Fletcher determined the charge on oil droplets in mechanical equilibrium.
Millikan and fletcher determined the charge on oil droplets in mechanical equilibrium
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Answer:
20.03g
Explanation:
This is the formula for percentage yield:
Percentage yield = Actual Yield / Theoretical yield
Rearrange it to get the Actual yield, which would be:
Actual yield = Percentage yield (in decimal form) x Theoretical yield
We know that 75% of CO2 is produced as the percentage yield in a reaction and the theoretical yield for the mass we're supposed to find is 26.7 grams.
Percentage yield in decimal form: 0.75
Theoretical yield: 26.7g
Plug it in the equation
Actual yield = 0.75 x 26.7g
Actual yield = 20.03g
for the reaction, Pb(no3)2 + 2kI yields pbi 2 + 2 kno3, how many moles of lead iodine are produced from 300 g of potassium iodine
Would an alkaline earth metal make a good replacement for tin in a tin can?
Answer:
Definitely not. This is because the alkaline earth metal [basically group 2 elements] are reactive and will react with the contents of the can, contaminating it.
No, alkaline earth metals would not be a good replacement for tin in a tin can because alkali from alkaline earth metals react with tin and release hydrogen.
What are alkaline earth metals?Alkaline earth metals are present in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
They are called alkaline earth metals because their hydroxide and oxides are highly alkaline. Their metal oxides are found in the earth's crust.
These metals have 2 electrons in their outer shell, and they are highly reactive, so they will react with the tin in a tin can.
Thus, alkali from alkaline earth metals react with tin and generate hydrogen, hence they would not make an acceptable replacement for tin in a tin can.
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a magnesium ion has 12 protons and a charge of 2 . how many electrons does it contain?
Answer:
It contains 12 electrons.
Help please I don’t know what to do
is change in color a physical change
Answer: A change in color is not always a chemical change. If one were to change the color of a substance in a non-chemical reaction scenario, such as painting a car, the change is physical and not chemical.
Solid → Liquid: Melting
Solid → Gas: Sublimation
Liquid → Gas: Vaporization
Gas → Liquid: Condensation
Explanation:
Welcome to my attic. I'm positive
that there are a lot of metals in
here.
Answer:
Gold Iron Titanium Lithium
Explanation:
Which statement describes how a substance melts?(1 point) Molecules in the substance gain kinetic energy and then become less tightly bound to each other. Molecules in the substance gain kinetic energy and then become less tightly bound to each other. Molecules in the substance lose kinetic energy and then become more tightly bound to each other. Molecules in the substance lose kinetic energy and then become more tightly bound to each other. Molecules in the substance lose kinetic energy and then become less tightly bound to each other. Molecules in the substance lose kinetic energy and then become less tightly bound to each other. Molecules in the substance gain kinetic energy and then become more tightly bound to each other. Molecules in the substance gain kinetic energy and then become more tightly bound to each other.
Answer:
Molecules in the substance gain kinetic energy and then become less tightly bound to each other.
Explanation:
According to the forces of attraction , for a substance to melt molecules in the substance gain kinetic energy and then become less tightly bound to each other.
What are forces of attraction?Forces of attraction is a force by which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
The physical properties such as melting point, boiling point, density are all dependent on forces of attraction which exists in the substances.
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Some acids like acetic acid and tartaric acid cannot be tasted
TRUE OR FALSE
The statement is a false.
An acid is a substance which when dissolved in water, produces hydroxonium ion, as the only positive ion.
Some properties of acid include:
They have sour tastes andStrong acids are corrosive.There are two types of acids which includes:
Strong acids: These are the acids that ionizes completely in solution.Weak acid: These are the acids that ionizes incompletely in solution.Examples of weak acid is acetic acid and tartaric acid.
They can be used as food substances like vinegar and naturally occurs on fruit like banana or grape.
Therefore, weak acids such as acetic acid and tartaric acid can be tasted.
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The given statement is False.
Some acids like acetic acid and tartaric acid can be tasted.
Organic acids, such as acetic, citric, malic, and fumaric acids in fruits and vegetables, and tartaric acid in wine, contribute significantly to the sour flavor of foods and beverages. Many inorganic acids taste sour in dilute solutions.
Tartaric acid is fairly water soluble and has a pronounced tart flavor. Tartaric acid is present naturally in grapes and bananas and has been shown to improve the flavor of grape and lime-flavored beverages. Tartaric acid may aid in the treatment of glucose intolerance and digestion.
Acetic acid is a colorless liquid having a sour flavor. Although it is most frequently associated with vinegar, this acid has a wide range of different applications in a variety of industries. Acetic acid is a colorless liquid that is composed of chemical compounds.
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Find the molar mass of iron (III) nitrate, Fe(NO3)3
Answer:
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which particle diagram shown above best represents the strongest intermolecular force between two ethanol, c2h6o, molecules?
The strongest intermolecular bonding in ethanol is hydrogen bonding.
Intermolecular forces are the forces that hold two molecules of a substance together in a given state of matter. For ethanol, the strongest intermolecular force is hydrogen bonding.
Hydrogen bonding occurs when hydrogen is directly linked to a highly electronegative element such as oxygen, nitrogen, fluorine or sulfur. The existence of intermolecular hydrogen bonds accounts for unusual properties such as abnormally high melting and boiling points.
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what species has an atom with an oxidation number of 3
Calculate the molar mass for CO
Answer:28.01 grams
Explanation:
Calculate the following examples.
1. Ramji conducted an experiment in the field related to the rate of percolation. He observed that it took 30 minutes for 600 ml of water to percolate through the soil. Calculate the rate of percolation per hour.
2. Jigna takes 50g of dry powdered soil in a filter paper and slowly adds water to the soil from a 100 ml fully filled measuring cylinder. When water starts dripping from the filter paper, 60 ml of water is left in the measuring cylinder. Find out the percentage of water absorbed by the soil.
Answer:
12ml per hour and
69% LOL
1) The rate of percolation would be 0.33 ml/s
Percolation rate = volume of water/time
= 600/1800s
= 0.33 ml/s
2) The percentage of water absorbed would be 40%
Percentage of water absorbed = amount absorbed/total water x 100
amount of water absorbed = 100 - 60
= 40 ml
total amount of water = 100 ml
Percentage of water absorbed = 40/100 x 100
= 40%
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which best explains why water dissolves most salts?
Answer:
where are the answers?
Explanation:
calculate the number of atoms in a sample containing 3.5 g of silicon atoms
Answer:
there are 7. 505 x 1022 atoms in 3.5 grams of silicon.
Explanation:
So, 1 mole of silicon will have a mass of 28.0855 g and the number of atoms will be 6.022 x 1023. Therefore, there are 7. 505 x 1022 atoms in 3.5 grams of silicon.
Answer:
1 mole of silicon will have a mass of 28.0855 g and the number of atoms will be 6.022*1023 . Therefore , there are 7.505*1022 atom in 3.5 g of silicon .
when a tennis ball is dropped from a high distance is it elastic or inelastic collision? explain?
Answer:
An elastic collision.
Explanation:
When a ball is dropped to the ground, one of four things may happen: It may rebound with exactly the same speed as the speed at which it hit the ground. This is an elastic collision.
How many moles of water is 5.02x1018 molecules
of water?
Answer:8.334×10^-6 moles
Explanation:
a mole is 6.023×10^23
5.02×10^18 ÷ 6.023×10^23=8.33×10^-6
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Answer this question and I will mark you the braninliest! <3
Answer:
the left one
Explanation:
heavier means it goes faster
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Use the key above to interpret the following incomplete chemical reaction.
Select the statements at apply in order to complete the model. (Choose 3)
A) The number of atoms in the products must be equal to the reactants.
B) One diatomic oxygen should be removed from the reactant side.
C) One unbonded carbon atom should be added to the product side of the equation
D) One carbon atom and two oxygen atoms are needed to balance the equation.
E) One carbon dioxide molecule should be added to the product side of the equation.
Answer:
Carbon dioxide molecule
Answer:a , d ,e
Explanation:
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