Question

1. the three particles that make up an atom are

a. protons, neutrons, and isotopes
b. neutrons, isotopes, and electrons

1. the space surrounding the nucleus of an atom contains

a. protons
b. electrons

1. the nucleus is made up of

a. protons and electrons
b. electrons and neutrons

1. if an atom contains 11 protons and 12 neutrons, its atomic number is

a. 1
b. 11

1. which of the following makes up a molecule of water?

a. one atom of hydrogen and one atom of oxygen
b. one atom of sodium and one atom of chlorine
c. one atom of hydrogen and two atoms of oxygen
d. two atoms of hydrogen and one atom of oxygen

1. a covalent bond is the result of

a. transferring electrons
b. sharing an electron pair

1. what type of electrons is available to form bonds?

a. valence
b. nucleus

1. what type of ion forms when an atom loses electrons?

a. neutral
b. positive

1. ice floats on water because

a. of cohesion
b. ice has a higher density than water
c. water shrinks when it freezes
d. ice has a lower density than water

Explanation:

1. Atoms are made of protons, neutrons, and electrons. Isotopes are different forms of an element, not a fundamental particle making up an atom.
2. Electrons orbit in the space surrounding the nucleus.
3. The nucleus consists of protons and neutrons.
4. The atomic number is equal to the number of protons. Here, with 11 protons, the atomic number is 11.
5. A water molecule (H₂O) is composed of two hydrogen atoms and one oxygen atom.
6. A covalent bond is formed by sharing an electron - pair.
7. Valence electrons are the electrons available for bonding.
8. When an atom loses electrons, it forms a positive ion (cation) as it has more protons than electrons.
9. Ice floats on water because ice has a lower density than water.

Answer:

1. Protons, neutrons, and electrons
2. Electrons
3. Protons and neutrons
4. 11
5. Two atoms of hydrogen and one atom of oxygen
6. Sharing an electron pair
7. Valence
8. Positive
9. Ice has a lower density than water