At 79.0°C, the volume of a gas is 49.0 L. If the pressure remains constant, at what
temperature will the volume be equal to 24.5 L?

At constant Pressure V /T = constant. s

49 / 79 = 24.5 / T

T = 24.5 × 79/49 = 39.5°C

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.

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