3. Sam needed to find a special zinc screw to fix the handlebars on her bike . When she went the garage , she found two unlabeled jars containing two different metal screws . Sam used water displacement to measure the following for each of the two screws she found :

	Mass ( g )	Initial volume of water ( mL )	Final volume of water ( mL )
Screw # 1	2.50	2.65	3.00
Screw # 2	2.55	2.55	2.87

Calculate the density for each screw . Then using the information above and Table I from the background determine the identity of each of the screws .

a . Screw # 1 has a density of _______ and is _______

b . Screw # 2 has a density of _______ and is ________