PLEASE! 46 POINTS!

1.-There are millions of unique substances in the universe because elements can combine in many different ways to form _____.
A.-mixtures
B.-solutions
C.-compounds
D.-ions

2.- Water is an example of a(n) _____.
A.-unique substance
B.-chemical compound
C.-covalent compound
D.-all of the above

3.- Which statement is true about water and hydrogen peroxide?
A.-Both substances have the same properties.
B.-Both substances have the same chemical formula.
C.-Both substances consist of hydrogen and oxygen
D.-Both substances are mixtures of elements.

4.-. Chemical bonds always involve _____.
A.-ions
B.-atoms
C.-metals
D.-electrons

5. The ratio of elements in a given compound _____.
A.-is always 2 to 1
B.-is always the same
C.-may vary
D.-two of the above

6. An oxygen atom has eight valence electrons.
True
False

7. A molecule of carbon monoxide has two carbon atoms and one oxygen atom. True
False

8.- The types of bonds in chemical compounds determine many of their properties.
True
False

9.- The same elements may form different compounds.
True
False

10.- The chemical formula for carbon dioxide is CO2.
True
False