B. Explain the trend in Question 2a. (Comparing the element at the top of the group with the element at the bottom of the group, what happens to the value of n for the valence electron? What does n inform
us of? What kind of force exists between an electron in the valence shell and the electrons in the core
shells?

chemical energy is stored in the chemical bonds of atoms and molecules. it can only be seen when it is released in a chemical reaction. when chemical energy is released, the substance from which the energy came is often changed into an entirely different substance.

this chemical reaction releases energy in the form of light and heat. chemical energy is the potential energy stored in the arrangement of atoms within molecules. breaking chemical bonds requires energy, while forming new chemical bonds releases energy.

the atp molecule can store energy in the form of a high energy phosphate bond joining the terminal phosphate group to the rest of the molecule. in this form,energy can be stored at one location, then moved from one part of the cell to another, where it can be released to drive other biochemical reactions.

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

: )