Chemistry 3

Question 1

Define chemical formula

Answer 1

identifies which elements and how many of each are in a compound

Question 2

What are some properties of ionic substances

Answer 2

high melting point
electrical conductivity when dissolved in water
distinct crystal shape
solids at room temperature

Question 3

What is an ionic compound

Answer 3

a pure substance formed by attraction between particles of opposite charges

Question 4

Define Ion

Answer 4

A charged particle

Question 5

Define Cations

Answer 5

Positive ions that have lost electrons. Metals tend to form cations

Question 6

Define Anions

Answer 6

Negative ions that have gained electrons. Non-metals tend to form Anions

Question 7

How are ion charges shown

Answer 7

a superscript of either a plus sign or a minus sign. (ex. Ca 2+)

Question 8

What are polyatomic ions

Answer 8

groups of atoms that when together have a charge.

Question 9

Define molecular compounds. How are they formed?

Answer 9

formed when nonmetals combine.

Some properties of molecular compounds are:
- low melting and boiling points (forces between molecules are weaker)
- poor conductors of electricity, good insulators
- can be solids, liquids or gas at room temperature

Question 10

What are the prefixes for numbers 1-10

Answer 10

1 mono
2 di
3 tri
4 tetra
5 penta
6 hexa
7 hepta
8 octa
9 nona
10 deca

Question 11

Molecular vs ionic

Answer 11

-Ionic Compounds tend to have high melting and boiling points
-usually solids at room temp
-conduct electricity

-Molecular compounds tend to have low melting and boiling points
-usually gases or liquids at room temp.
-do not conduct electricity