Which pair of elements would have the same number of valence electrons, in their neutral atoms?

a. lithium and beryllium
b. silicon and chlorine
c. germanium and lead
d. bromine and krypton

An observation that requires measurement is called quantitative observable or qualitative

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.

The picture represents the process that produces most of the energy used by living organisms on earth. which process is represented in the picture? a) the magnetic attraction between two hydrogen nuclei. b) the fusion of hydrogen nuclei to produce a helium nucleus in the core of the sun. c) the fission of hydrogen nuclei to produce a helium nucleus in the core of the sun. d) the chemical reaction between hydrogen nuclei to produce a helium nucleus in earth's atmosphere.