Which of the following indicates the percentage of the natural occurrence of an isotope of an element on the planet? A. Atomic mass
B. Atomic mass unit
C. Natural abundance
D. Isotope

hope this

explanation:

covalent bonds

consist of pairs of electrons shared by two atoms, and bind the atoms to fixed orientation and requre high energies to break them

ionic bonds

when two atoms differ considerably in their electronegativity, then one of the atoms will lose its electron to the other atom. this results in a positively charged ion(cation) and a negatively charged ion (anion)

your answer would be “dry”