The answer is (4) synthesis. Synthesis reaction means that two or more reactants combine directly to one production. Substitution or single replacement means that one element of a compound is replaced by another element. Double replacement means that two ionic reactants exchange ions to form two new productions.
No, Matter cannot be created nor deastroyed.
Answer:
2NaCN + CaCO3 --> Na2CO3 + Ca(CN)2
Explanation:
Knowing the names gets us: NaCN + CaCO3 --> Na2CO3 + Ca(CN)2
Balance: there are two sodiums and cyanides on the product side so add a 2 to the reactant side.
The atomic mass or relative isotopic mass refers to the mass of a single particle, and therefore is tied to a certain specific isotope of an element. The dimensionless standard atomic weight instead refers to the AVERAGE of atomic mass values of a typical naturally-occurring mixture of isotopes for a sample of an element.
You can count it by yourself using formula
m = ({first isotopic distribution%}× {first atomic.mass})+ ({second isotopic distribution%}× {second atomic.mass}) / {100}
