Convert 2.50 x 10^5 seconds into years

What substance has a mass of 9.5g and volume of 2.1cm^3

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.

In which block of the periodic table is uranium (u) found? s blockd blockp blockf block