The electron affinity of an element is positive if energy is absorbed during the process of accepting an electron and negative if energy is released during the process. Using the electron configuration of the atom or ion undergoing the addition of an electron, predict whether the electron affinity will be positive or negative for the following reactions, and classify them accordingly. Na(g)+ 1e^- → Na^-(g)
Mg(g)+1e^- → Mg^-(g)
Br(g)+ 1e^- → Br^-(g)

See explanation

Explanation:

Electron affinity is the energy released when an extra electron is added to a neutral gaseous atom. A negative value of electron affinity indicates that energy is given out and vice versa.

Metals have positive electron affinity since electrons rarely accept electrons, so;

Na(g)+ 1e^- → Na^-(g)      positive

Mg(g)+1e^- → Mg^-(g)      positive

For the last case; Br(g)+ 1e^- → Br^-(g), the electron affinity for the non-metals is negative. hence the answer

hloride, what is the mass of calcium in

explanation:

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.