Elements in group 1-2, 13-18, the number of valence electrons is related to the group number. For example, in the first group, the alkali metals there is one valence electron, however in group 13, there are 3 valence electrons. Valence electrons are also known as the outershell electrons.
Answer: a) : Decomposition
b) : double displacement
c) : Synthesis (Combination)
d) : redox
Explanation:
Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.
A double displacement reaction is one in which exchange of ions take place.
Synthesis reaction is a chemical reaction in which two reactants are combining to form one product.
Redox reaction is a type of chemical reaction in which oxidation and reduction takes place in one single reaction. The oxidation number of one element increases and the oxidation number of other element decreases.
Answer:
I think it's B " Constraints are more important than criteria ".
All atoms of the same element have the same
number of protons. Every atom also has a nucleus.