Question

1. which element has a full valence shell and is therefore unlikely to react? mark only one oval. sodium (na) chlorine (cl) neon (ne) calcium (ca) 22. a chlorine - 35 atom has. mark only one oval. 17 protons, 18 neutrons, 18 electrons 17 protons, 18 neutrons, 17 electrons 35 protons, 18 neutrons, 17 electrons 17 protons, 35 neutrons, 17 electrons 23. which particle has the least mass? mark only one oval. proton neutron electron nucleus 24. the mass number of an atom is equal to: mark only one oval. protons only neutrons only protons + neutrons protons + neutrons + electrons

Explanation:

21.

Noble gases have full valence shells and are chemically inert, less likely to react. Neon is a noble gas.

The atomic number of chlorine is 17, so it has 17 protons. Chlorine - 35 has a mass number of 35. Mass number = protons + neutrons, so neutrons = 35 - 17=18. In a neutral atom, number of protons = number of electrons, so 17 electrons.

Electrons have a much smaller mass compared to protons, neutrons and the nucleus (which contains protons and neutrons).

Answer:

B. Neon (Ne)

22.