Question

(1) Which statements are TRUE concerning particles that make up atoms? I. The mass comes solely from the neutrons. II. The atomic number of a neutral atom equals the number of electrons and the number of protons. III. The protons and the neutrons are contained in the nucleus

A. I and II

B. I and III

C. II and III

D. I, II, and III

(2). Which statement is FALSE?

A. The atoms in ammonia are joined by covalent bonds.

B. The air around us is considered a mixture.

C. An ionic bond results from the transfer of one or more electrons from one atom to another.

D. Sodium and chloride ions arrange themselves into discrete molecules of NaCl as represented in ball-and-stick models.

Answer 1

(1) C. II and III

False: I. The mass comes solely from the neutrons. Because mass is equivalent to the number of protons and neutrons in the atom.

True: II. The atomic number of a neutral atom equals the number of electrons and the number of protons.

True: III. The protons and the neutrons are contained in the nucleus

(2) False D. Sodium and chloride ions arrange themselves into discrete molecules of NaCl as represented in ball-and-stick models. Because NaCl iomic compound do not exist as discrete molecule. Instead they exists as crystal where ions of opposite charges occupy position known as lattice sites