Chemistry/Science Question.?

Question

Identify each of the following elements:

a. a member of the same family as oxygen whose most stable ion contains 54 electrons.

b. a member of the alkali metal family whose most stable ion contains 36 electrons.

Explain your answer please.

Answer 1

Atoms are made up of

protons - positively charged particles

neutrons,- neutral charge

and electrons - negatively charged

protons and neutrons are located in the nucleus of the atom.

electrons wizz around the nucleus in orbitals

The number of protons in the nucleus defines what element it is. The number of protons in the nucleus is the Atomic number of the element.

For example

Oxygen, has an atomic number of 8. It has 8 protons in it's nucleus. Any atom with 8 protons has to be oxygen.

If you have an element that has 6 protons in its nucleus is Carbon.

etc.

The number of neutrons can vary, but protons must always be the same for a particular element.

In a neutral atom, the number of protons equals the number of electrons in the atom.

Neutral oxygen has 8 protons, so it also has 8 electrons.

However, atoms also like to have full outer electron shells. The reason atoms gain or loose electrons is to  get a full outer shell.

The periodic table is organised so that elements in columns going down periodic table all have the same number of electrons in their outer shell.

Oxygen is in group 6, it has 6 electrons in it's outer shell.

Group 6 elements would all like to have 8 electrons in their outer electron shell. This would give them electronic stability.

For this reason, all elements in group 6 will gain 2 electrons to give themselves a full outer shell, thus forming an ion with a charge of -2, because you now have 2 more electrons then protons.

a) The element is in group 6 with Oxygen, it is at it's most stable, thus has 2 extra electrons to give it a full outer shell of 8 electrons. Therefore it must have 54-2 protons = 52. So it's atomic number is 52.

The element with atomic number 52 is Tellurium (Te).

b) alkali metals is the name given to group 1 elements.

as with the previous example, all group 1 elements have the same number of electrons in their outer shell.

Group 1 = 1 electron in outer shell.

All atoms in group 1 want a full outer shell, They will all lose 1 electron to form an ion with a +1 charge, because now there is one less electron.

So, if the element is in group 1 and is stable (has 1 less electron then proton) then it must have 36 + 1 = 37 protons,

thus its atomic number is 37

This is Rubidium (Rb)