X is an element with the following properties: • melts at -220°C and boils at -188°C;
does not conduct electricity at room temperature:
forms molecular compounds with non-metals;
forms ionic salts with metals in which its ion has a 1-charge.
Would you expect X to be a solid, a liquid or a gas at 20°C? IS

organisms are more likely to be more preserved in mud than sand because mud is moist and wet, while sand is very dry.

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume

a is the correct answer

i think it's letter a.