Write a ground state electron configuration for these ions. remember that ions have a
change in the total number of electrons (positive have lost electrons and negative have
gained). example: n3.is 1s 2s 2p. it has three extra electrons
11. 02-
13. b3+
15. k
12. fe2+
14. ni2+
16. co3+
17. if each orbital can hold a maximum of two electrons, how many electrons can each of the
following hold?
a. 2s
c. 4f
e. 4d
b. 5p
d. 3d
18) isoelectronic species have similar electron configurations. which of these are isoelectronic?
a) li*, h, he
b) ca2+, ne, s?

one negative thing it that it can kill water animals. another negative thing is it can cause the destruction of ecosystem. one way water pollution can be reduced is to conserve energy.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.