Answer: Aluminium
Explanation: Aluminium metal has a lower density than copper. So, for the same volume of metal used to build a model airplane, the aluminium plane would be very lightweight while that of copper would be heavy. The lightweight airplane will fly easily.
The change in the velocity = 4 m/s
Acceleration = 4 m/s²
<h3>Further explanation</h3>
Given
vo = initial velocity = 4 m/s
vf = final velocity = 8 m/s
t = 1 s
Required
The change in the velocity
Acceleration
Solution
the change in velocity =

Acceleration = ratio of a change in velocity and the time

Input the value :

Explanation:
Atomic radius decreases from left to right in a period.
Therefore Calcium would have a smaller atomic size.
The volume of a gas is the same as its CONTAINER.
Gases generally has no shape and no definite volume. When a gas is placed in a container, the gas usually takes the shape and the volume of the container, that is, the gas fills up all the available spaces in the container. Thus, the volume of a gas will always be the same as its container. This is in contrast with solids, which have definite shape and volume and liquids, which have definite volume but no fixed shape.