Answer:
Ghana Empire is was a kingdom in western Africa.
The amount of carbon in fossils and artifacts decreases when the get older, so you can find out how old an object or fossil is by finding out how much carbon is in it.
Answer:
carbon and silicon
Explanation:
Various groups of elements in the periodic table have different outermost shell electron configurations. Actually, elements are classified into groups on the basis of the number of electrons on the outermost shell of those elements. All elements with the same number of electrons on their outermost shell belong to the same group in the periodic table.
For elements in group 14, they all have four electrons on their outermost shell. Their general outer electron configuration is ns2 np2 as shown in the question. Two prominent members of this group are carbon and silicon. This ns2 np2 is the ground state outer electron configuration of all group 14 elements in the periodic table.
Answer:
Li2S> Na2S> K2S> CsS
Explanation:
The lattice energy of ionic species depends on the relative sizes of ions in the ionic compounds. As the size of ions increases, the lattice energy decreases and vice versa.
When the size of the anions are the same, the lattice energy now depends on the relative sizes of the cations. Therefore, since all the compounds are sulphides and the order of magnitude of ionic sizes is: Li^+ < Na^+ < K^+ < Cs^+.
Therefore, the order of decrease in lattice energy is; Li2S> Na2S> K2S> CsS
