The answer is they follow a patter for valence electrons.
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.
I believe the answer is C
Answer:
60%
Explanation:
M(NH4NO3) = 2*14 +4*1 +3*16 = 80 g/mol
M(3O) = 3*16 = 48 g/mol
(48/80) *100 % =60% oxygen by mass.
Answer: 
< 0
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.
For the reaction 
In this reaction gaseous reactants are converting to solid products. The randomness will decrease and hence entropy will also decrease. Thus is negative or less than zero.
