When the temperature increases the atoms gain energy and the substance changes into a gas state.
The is the opposite when the temperature decreases and the liquid becomes solid ( in this case ice).
Density = mass divided by volume. 15/30 is 1/2 so the density is 1/2 or 0.5 g/cm
Alpha particles, also called alpha ray or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a <u>helium-4 nucleus. </u>They are generally produced in the process of alpha decay, but may also be produced in other ways.
Composition: 2 protons, 2 neutrons
Mass: 6.644657230(82)×10−27 kg; 4.0015061...
Electric charge: +2 e
Symbol: α, α2+, He2+
