Sci 9 Unit 2 Review

Question 1

J.J. Thomson proposed the theory that

Accepted Answer

electrons are embedded in the nucleus like raisins in a bun

Question 2

An unknown compound was discovered to have the formula X3Y2. What is the ion charge of the unknown element Y?

Accepted Answer

3-

Question 3

A mixture where you can see the different substances is called

Accepted Answer

heterogeneous, mechanical

Question 4

1. The chart represents the steps in classifying matter. What does the category labeled A represent:

Accepted Answer

Pure Substances

Question 5

In which of the following scenarioes does a chemical reaction occur?

Accepted Answer

a wood fire burns

Question 6

Sodium is in the first column on the left, this means it is in group 1

Accepted Answer

True

Question 7

To increase the rate of a reaction you could...

Accepted Answer

add a catalyst, increase the temperature, increase the surface area of the reactants, increase the concentration of the solute

Question 8

What does the atomic number tell us about an atom?

Accepted Answer

number of protons

Question 9

Carbon has 6 protons and an atomic mass of 12.01. How many neutrons and electrons does it have, respectfully

Accepted Answer

6, 6

Question 10

this group of elements often combine with metals to form ionic compounds called salts

Accepted Answer

halogens

Questions 10