Homework Chemistry 8

 

Directions: Answer the questions in complete sentences below.

 

1) Where is the atomic number and atomic mass of an element? What does the number tell you?

 

 

 

 

2) What is the difference between an ionic or covalent bond?

 

 

 

 

3) What kind of bond occurs between a non-metal and a non-metal, like when H binds with H?

 

 

 

 

 

4) What kind of bond occurs between a metal and a non-metal, like when Sodium binds with Chlorine?

 

 

 

 

5) What are valence electrons? How many does Group 15 have?

 

 

 

 

 

 

6) Why are valence electrons important?

 

 

 

7) What is the difference between endothermic and exothermic?

 

 

 

8) What happens to the energy in a system when you break a bond?

 

 

 

9) What happens to the energy in the system when you make a bond?

 

 

 

 

10) Where is most of the mass found in an atom? Why?

 

 

 

 

11) What happens when you join positive and negative ions together?

 

 

 

 

12) What happens when you place a weak acid in water?

 

 

 

 

13) What happens when you place a strong acid in water?

 

 

 

 

14) Where are the most reactive elements in the periodic table found? Why?

 

 

 

15) All transactinide elements are also transuranium elements, that is, have an atomic number greater than that of uranium (92), an actinide. Transuranium elements are made in a lab using a nuclear accelerator. Name 3 of the transuranium elements.

 

 

 

16) How many valence electrons does the alkali and alkaline metals have?

 

 

 

17) When an acid is mixed with a base, what is formed? Why?

 

 

 

 

18) Acids turn pH paper red. Bases turn them what color?

 

 

 

19) What elements often share electrons to make large compounds?

 

 

 

 

 

20) Why did we use a pH meter? What kind of information did the pH meter give us?