I am assuming you are talking about Neon. The rate of diffusion is directly proportional to the molar mass of the gas. Since neon has a molar mass of 20.18 grams, the gas must have a lower molar mass and must be a gas at 273 Kelvin. There are several elements that fulfill this criteria: Hydrogen, Helium, Oxygen, Nitrogen, and Fluorine.
The atom has equal amount of Protons and electrons it is Neutral
The answer to 4 is A.
The answer to 5 is C.
Answer:
The nucleus consists of 25 protons (red) and 30 neutrons (blue). 25 electrons (green) bind to the nucleus, successively occupying available electron shells (rings). Manganese is a transition metal in group 7, period 4, and the d-block of the periodic table. It has a melting point of 1246 degrees Celsius.