Year 10 chemistry exam revision

1. Which of the following is true about atoms?

• Are the smallest particle in the universe

• Contains a nucleus of protons and electrons

• Can be split into molecules and compounds

• Contains a nucleus of protons and neutrons

An element, X, has the following electron configuration: 2, 5. The atomic number of element X would be

• 2

• 5

• 7

• 3

Which one of the following lists of sub-atomic particles constitutes an ion?

• 17 protons, 18 neutrons, 18 electrons

• 8 protons, 8 neutrons, 8 electrons

• 1 proton, 0 neutrons, 1 electron

• 92 protons, 146 neutrons, 92 electrons

This is a diagram of a chlorine atom. What is the electron configuration of this atom?

• 2, 8, 7

• 2, 7, 8

• 8, 7, 2

• 10, 7

Would Chlorine accept or donate electrons to become an ion?

• Accept

• Donate

• Share

• Chlorine is a noble gas so it does not have to become an ion.

Chlorine has 7 electrons in its outer shell. It needs 1 more to have a full outer shell and be content. What is the ion symbol for a chlorine atom that has filled its outer electron shell?

• +1

• -1

• +7

• -7

Look at the symbol for Sodium. What is the atomic number for sodium?

• 34

• 23

• 12

• 11

What is the mass number of sodium? (Round to the nearest whole number).

• 11

• 22

• 23

• 12

How many protons an electrons does sodium have?

• 11

• 12

• 23

• 22

How many neutrons does sodium have? (Round the mass number to the nearest whole number)

• 34

• 22

• 23

• 12