Answer:
Atoms
Explanation:
According to the law of conservation of matter, matter is neither created nor destroyed, so we must have the same number and kind of atoms after the chemical change as were present before the chemical change.
Buckminster fullerene C60
Answer:
The volume of the piece of iron is 5.18dL.
Explanation:
The density (ρ) is equal to the mass (m) divided the volume (V).

If we rearrange it, we have:

To express the volume in dL we will need the following relations:
- 1 dL = 0.1 L
- 1 kg = 10³ g
- 1 cm³ = 1 mL
- 1mL = 10⁻³L
Then,

Finally,

Answer:
A body becomes weightless in a zero-gravity scenario and when a force is applied to a body that is equal and opposite to the force of gravity. If the body is falling only under the influence of gravity.