Answer:
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American spelling) is a unit of length in the metric system, equal to one billionth (short scale) of a metre (0.000000001 m).
In the context of chemistry, yes. Energy input is always equal to the energy output.
A DNA and chromosomes are found in different types of cells
The correct answer is elements in family 7 have similar properties because elements in the same group or family have the same number of valence electrons.