The mass of gas particle affects the rate of effusion by decreasing the rate as the mass increases. This describe by the Graham's Law of Effusion where the rate of effusion is inversely proportional to the square root of the molar mass of a substance. Hope this helps.
The third one beacuse if you count all the atoms of every one you will find that one the left side, you have 3 h and on the right you have 2 h
Substances have different tendencies to donate or accept electrons. When a really good donor meets a great acceptor, the chemical reaction releases a lot of energy. Oxygen (O2) is the best electron acceptor and is used in many aerobic reactions (reactions with oxygen). Hydrogen gas (H2) is a good electron donor.
When O2 and H2 are combined, along with a catalyst, water (H2O) is formed. This example of a redox reaction can be written like this:

FBI Fedral Burea of Investagation
Gamma rays contain much more energy (most penetrating) than radio waves because they have a greater frequencies.
Radio waves are the electromagnetic waves with the longest wavelengths (1dm to 100 km), lowest frequencies (3kHz to 3GHz) and lowest energy (124 peV to <span>12,4 μeV).
</span>Gamma rays are the electromagnetic waves with the shortest wavelengths (1 pm), highest frequencies (300 EHz) and highest energy (1,24 Me<span>V</span>).