Which of the following statements is not a part of john dalton's atomic theory?
electrons move in specific orbits around the nucleus of an atom.
all elements are composed of atoms that cannot be divided.
all atoms of the same element are exactly alike and have the same mass.
every compound is composed of atoms of different elements, combined in a specific ratio.

The statement that is NOT a part of John Dalton's atomic theory Electrons move in specific orbits around the nucleus of an atom. The statements ‘All elements are composed of atoms that cannot be divided’, ‘All atoms of the same element are exactly alike and have the same mass’ and ‘Every compound is composed of atoms of different elements, combined in a specific ratio’ are not his theory.

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms