Atoms and atomic structure

1. The atoms in an element are:

All the same type
Two types joined together
About a hundred different types

2. An atom consists of:

An electron surrounded by a nucleus
A nucleus containing electrons
A nucleus surrounded by electrons

3. What is the correct chemical symbol for sodium?

NA
Na
na

4. What do we get when two or more different types of atom join together using chemical bonds?

A mixture
A compound
A new element

5. What are the groups in the periodic table?

A row of similar elements
A column of similar elements
The boxes in the table

6. What do chemical bonds involve?

A nucleus moving from one atom to another
Electrons being transferred from one nucleus to another
Electrons being shared between two atoms

7. A unit of magnesium carbonate contains one magnesium atom, one carbon atom and three oxygen atoms. What is its chemical formula?

MgC₃O
Mg(CO)₃
MgCO₃

8. Which statement about chemical reactions is correct?

The mass of products equals the mass of reactants
The mass of products is more than the mass of reactants
The mass of products is less than the mass of reactants

9. The correct balanced equation for the reaction between magnesium and oxygen is:

Mg + O ==> MgO₂
Mg + O₂ ==> Mg₂O
2Mg + O₂ ==> 2MgO