Does anybody know which element from the periodic table that has 19 electrons and 24 neutrons, for atomic charge.

A1.5l container holds p.50 grams of an unknown gas at a pressure of 0.44 atm and a temperature of 50.c what is the molar mass of the unknown gas

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?

The student repeated the experiment using a higher concentration of acid. the same volume of acid and the same mass of magnesium ribbon were used. what volume of hydrogen gas would have been produced after 60 seconds?