Answer:
C
Explanation:
electronic waves transmits energy but mechanical waves require a medium in order to transport their energy from bgg one place to another.
No one can do that by him or her self
Ca^2+ and I^-
Na+ and Co3^2-
Ga^3+ and ClO3
Cu^2+ and F-
NH4^- and PO4^3-
Fe2+ and (SO4)^2-
Mg2+ and NO3^-
NH4^+ and NO2^-
K^+ and (C2H3O2)^- {C2H3O2 is acetate}
Na^+ and Cr2O7^2-
An element is a pure substance that cannot be separated or divided into simpler substances by any method (physical or chemical). The four common elements in all the living organisms are carbon, oxygen, hydrogen, nitrogen.
Thus, the four elements that make up about 96 % of body matter are carbon, oxygen, hydrogen, nitrogen (c).