Answer:
Gases are compressible, meaning that when put under high pressure, the particles are forced closer to one another. This decreases the amount of empty space and reduces the volume of the gas. Gas volume is also affected by temperature. When a gas is heated, its molecules move faster and the gas expands.
Group 4A
The elements in group 4 show the most diverse set of properties.
The brain. The brain tells the body what to do same way the nucleus does for the cell.
Alpha particle has a mass of 4 (Two protons and two neutrons)
Neutron has a mass of 1
Beta particle has a mass of about 0 (Electron)
Proton has a mass of 1
So the answer is (2) Beta particle