Strontium chemistry question

Question

does an atom of strontium gain or lose electrons when forming an ion how many electrons are gained or lost by the atom? and when strontium forms an ion, the ion has the same number of of electrons as which one of the noble gases.

im a little lost, can somebody maybe explain a little?

thanks

Answer 1

) use the periodic table

2) every element in each column (vertical) has a charge, this charge is positive (cation) or negative (anion)

Have you heard of the octet rule? Evey atom of any element wants 8 electrons in it's outer shell.

How do you know which element wants how many? You look

at the periodic table and depending on what group the element is in it wants to gain or lose a certain amount of electrons.

If in group 1-A like Li (lithium) then it wants to lose one electron because it already has a shell of 8 electrons underneath.

All elements in groups 1-A,2-A,3-A,or 4-A want to lose electrons and those in groups 4-A,5-A,6-A,7-A want to gain electrons.

Group 4 can either gain or lose electrons and group 8 already has an octet(8 electrons in outer shell) so it doesn't react with other elements. Basically you just make the ratio by seeing when the two elements combine that their charges add up to zero.

ex) Li (+1) and B(+3) ()=charges. formula is Li3B. If an atom has less than 4 electrons in it's outer shell like those in groups 1-A,2-A, and 3-A, they lose electrons getting a positive charge and if in groups 4-A,5-A,6-A, or 7-A they gain electrons getting a negative charge. The ratio has to make the two elements combining to make an ionic compound where charges add up to equal zero.

Answer 2

Sr, being a group 2 metal will loose two electrons to from the ion, Sr2+.  It does this to achieve a stable electron form similar to Krypton.

Molecules like to assume a state of lowest energy, this is usually in the form of an octet (8) of electrons in it's outer electron shell.  All noble gases have that octet and therefore do not tend to react.  

The closest noble gas to Sr is Kr. The loss of two electrons leave Sr with the same electron configuration as Kr.

Answer 3

Sr is an element of group 2.It has 2 electrons on its valence shell and so gives easily these 2 electrons to form the bivalent cation Sr++ which has the same electonic shell as the inert gas Kr

The Z of Sr =38

so electronic structure

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6  5s2

the electrons 5s2 are removed for ionSr2+