I don’t understand! Please help :( Just answering one of them will be helpful enough. Much appreciated.

For each of the following elements, indicate which set of orbitals is being filled last: tungsten, iron, europium, cerium, uranium.

Why is soap used to remove grease? a. its nonpolar end dissolves the grease. b. it makes the water bond with the grease. c. it chemically bonds with the grease. d. its polar end dissolves the grease.correct answer for apex - a, its nonpolar end dissolves the grease.

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

How does a catalyst increase the speed of a reaction? a. the catalyst eliminates the activated complex stage, allowing products to form immediately. b. the catalyst lowers the energy level of the reactants, making it easier for them to react. c. the catalyst makes it easier for the activated complex to form, lowering the activation energy. d. the catalyst raises the energy level of the products, making the reaction finish sooner. reset next