Answer:
False
Explanation:
A double covalent bond means 2 atoms or elements are sharing <u>4</u><u> </u><u>e</u><u>l</u><u>e</u><u>c</u><u>t</u><u>r</u><u>o</u><u>n</u><u>s</u>.
*single covalent bond shares 2 electrons.
Answer: The missing coefficient is 2.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

As in the products, there are 2 atoms of sodium, thus there will be 2 atoms of of sodium in the reactant as well. This will balance the number of hydrogen and oxygen atoms as well.
Thus the missing coefficient is 2.
Answer:- A.
is not the correct formula.
Explanations:- Charge for Ba is +2 and charge for O is -2, Here the charges are in equal and opposite so their ratio is 1:1 and hence the formula must be BaO and not
.
Rest of the formulas are correct as charge for Ca is +2 and charge for N is -3 . On criss cross we get the formula
.
Charge for K is +1 and charge for Cl is -1 and so KCl is correct.
Charge for Li is +1 and that for S is -2. On criss cross we get the formula
.
A rising tide is also known as an occurrence between low tide to high tide.