Midterm Review Packet Answer Key - East Boston High School (Page 5 of 6) in pdf

Midterm Review Packet Answer Key - East Boston High School Page 5

c) This atom exists in a neutral state. How many electrons does it contain? How do you know?

9 electrons. In a neutral atom, the number of protons = the number of electrons

d) Draw a model of this atom

*on your diagram, be sure to indicate the numbe of protons and neutrons in the nucleus

e) Many of the atomic masses in your periodic table contain a decimal. The mass number above

(14 amu) is a whole number (it does not contain a decimal). Explain why.

The atomic masses in the periodic table are a weighted average of all the masses numbers of the

different isotopes of an element. The mass number above, 14 amu, is a whole number because it is the

mass of a single atom of fluorine, which is obtained by adding the total number of protons to the total

number of neutrons in this atom of fluorine.

Write the names of the following compounds (questions 59):

5. SO

s ulfur dioxide

6. N

dinitrogen dioxide

9. CuCO

c opper carbonate

8. Fe

iron (III) oxide

Write the chemical formula for the following compounds (questions 1116):

11. iron (III) oxide

F e

12. copper (II) nitrate

Cu(NO

)

13. sodium nitride

N a

14. potassium fluoride

K F

15. silicon tetrafluoride

SiF

16. nitrogen dioxide

N O

17. a. Draw a picture of two water molecules hydrogen bonding. Show the partial charges on the

molecules.

Midterm Review Packet Answer Key - East Boston High School Page 5