Question

PLEASE HELP ME!!!!!!!!!!!!!!!!!!!!!!!!!

1.) Which of the following is a molecule but not a compound?A.He
B.F2
C.H2O
D.CH4

2.) What is a physical combination of substances?
A.a compound
B.a molecule
C.a mixture
D.an element

3.) What is a chemical combination of substances?
A.a compound
B.an atom
C.a mixture
D.an element

4.) What is the relationship between the solute and solvent in a solution?
A.they form a compound
B.they form a mixture
C.they form molecules
D.they form chemical bonds

5.) The gases in air dissolve in water. What would be one way to reduce the amount of a gas dissolved in water? A.add more water
B.reduce the air pressure
C.increase the air pressure
D.stir the water

6.) How would you determine the solubility of a substance? A.Find how well it dissolved various substances.
B.Find the mass and the volume of the substance.
C.Find the temperature at which the substance evaporated.
D.Find how much I was able to dissolve in a solute.

7.) The periodic table organizes all of the kinds of A.molecules.
B.compounds.
C.atoms.
D.ions.

8.)What distinguishes two substances combined to become a compound vs. two substances combined to become a mixture?
A.whether they can be easily separated
B.whether they chemically bond together
C.whether they both are visible
D.whether they are heterogeneous

9.) The principle components of air are:
N2 78%
O2 21%
Ar 0.95%
CO2 0.038%

This is a solution of
A.molecules and atoms.
B.molecules.
C.compounds and molecules.
D.atoms.

Answer 1

1.) Which of the following is a molecule but not a compound?

A.He

"He" or helium is an initial for a single element and a compound has more than one element.

2.) What is a physical combination of substances?

A.a mixture

When two substances are combined they result in a compound.

3.) What is a chemical combination of substances?

A. they form a compound

When two chemical elements are combined they form a compound.

4.) What is the relationship between the solute and solvent in a solution?

B.they form a mixture

Solutes are dissolved into the solvent which results in a mixture.