A beta particle. Hoped I help. Sorry if it wrong.
The air inside becomes warmer, and that makes it LESS DENSE.
Less-dense air FLOATS in denser air. Since it's inside the balloon, it picks the balloon up when it floats.
Answer:
Tangential
Explanation: This is a kind of force which act on a moving body in such a way that it is curved in the direction of the path of the body. This implies that when the velocity of the object is positive, the acceleration will be negative.
B is the answer that I know of.
When an object absorbs an amount of energy equal to Q, its temperature raises by

following the formula

where m is the mass of the object and

is the specific heat capacity of the material.
In our problem, we have

,

and

, so we can re-arrange the formula and substitute the numbers to find the specific heat capacity of the metal: