2.6 compounds and formulae

Question 1

what is a compound

Answer 1

when more than 1 different types of atoms join together

Question 2

what is the chemical term for atoms joining together?

Answer 2

bonding

Question 3

what if a compound has a metal?

Answer 3

the metal comes first in the compound name

Question 4

what if a compound has a non-metal

Answer 4

the name of the non-metal is usually changed

Question 5

which 2 elements are combined in sodium chloride

Answer 5

sodium, chlorine

Question 6

which 2 elements were combined in hydrogen sulfide

Answer 6

hydrogen, sulfur

Question 7

which 2 elements are combined in magnesium oxide?

Answer 7

magnesium, oxygen

Question 8

why is the compound with calcium, oxygen, and carbon called ‘calcium carbonate’

Answer 8

some compounds contain 2 different elements, plus a third element—oxygen. these compounds often have names ending with ‘ate’

Question 9

suggest which 3 elements are in calcium nitrate

Answer 9

calcium, nitrogen, oxygen

Question 10

suggest the formula for carbon dioxide, and why the formula is like that

Answer 10

CO2

carbon dioxide consists of 1 carbon atom, and 2 oxygen atoms, so after oxygen, a ‘2’ means that there are 2 oxygen atoms

Question 11

is the symbol ‘NaCl’ a compound or an element? explain

Answer 11

compound, because there is ‘Cl’ meaning chlorine, and ‘Na’ meaning sodium

Question 12

the formula for calcium chloride is CaCl2, so how do you know how many chlorine atoms are combined with calcium atoms?

Answer 12

calcium: 1 atom
chlorine: 2 atoms

Question 13

the compound with the formula ‘CO’ is carbon monoxide, so suggest why it is not simply called ‘carbon oxide’

Answer 13

‘mono’ means 1, so if there is 1 atom of oxygen, it is called carbon monoxide

Question 14

suggest the names of the compound with this formula: MgO

Answer 14

magnesium oxide