Formulae & Equations

Question 1

Which element has a formula that shows its molecules contain two atoms joined together?

Answer 1

The formula of chlorine is Cl2. The subscript number 2 tells us that its molecules contain 2 atoms joined together.

Question 2

What is the correct formula for ammonia?

Answer 2

The formula of ammonia is NH3.

Question 3

Which of the following compounds is made up of molecules that contain five atoms?

Answer 3

Methane molecules contain five atoms as the formula is CH4, one carbon atom joined to four hydrogen atoms.

Question 4

Which of these compounds is most likely to contain ions?

Answer 4

Lead dioxide is most likely to contain ions as it is formed between a metal and a non-metal.

Question 5

Whats left of the arrow?

Answer 5

reactant

Question 6

Whats right of the arrow?

Answer 6

products

Question 7

What is the mnemonic for molecules that contain two atoms joined together?

Answer 7

iodine, I2
bromine, Br2
chlorine, Cl2
fluorine, F2
oxygen, O2
nitrogen, N2
hydrogen, H2
I Bring Clay For Our New House

Question 8

what are the charges for ZN,NH SO,OH,PB

Answer 8

ZN+2 : NH4+1 : SO4-2 : OH-1 : PB+2

Question 9

what are the charges fo NO : SO : CO

Answer 9

NO3-1 : SO4-2 : CO3-2