The volume of a gas is halved and the temperature is unchanged. the pressure of the gas is

this is base don Boyle law

PV= constant at constant temperature

P1V1=P2V2

here the V2= V1/2

P1 *V1 =P2* V1/2

P1 *2 = P2

it mean pressure of gas is doubled

The pressure will get doubled.

Explanation:

On the basis of the ideal gas equation, the pressure relies upon the gas constant, the number of moles, the volume of the gas, and the temperature. In the given case, the temperature is constant, and let us assume that the number of moles is also constant for a specific gas. Thus, the pressure only modifies with the change in volume. According to the equation, PV = nRT or P = nRT / V, the pressure is inversely proportional to the volume, thus, if the volume is reduced, the pressure will also get increase.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.