1.
Which of these is a property of an Ionic compound?
Correct Answer
C. Crystal shape
Explanation
Ionic compounds have high melting points, conduct electricity when dissolved in water, are shaped into crystals, and transfer electrons.
2.
Ions that are made of more than one atom are called:
Correct Answer
D. Polyatomic ions
Explanation
Polyatomic ions are ions that are composed of more than one atom. They are formed when a group of atoms gain or lose electrons to become charged. Unlike molecules, which are held together by covalent bonds, polyatomic ions are held together by ionic bonds. Isotopes, on the other hand, are atoms of the same element with different numbers of neutrons. Therefore, the correct answer is polyatomic ions.
3.
Ionic bonds form because:
Correct Answer
B. Two ions of different charges are attracted to each other
Explanation
Ionic bonds form because two ions of different charges are attracted to each other. In an ionic bond, one atom donates electrons to another atom, resulting in the formation of positive and negative ions. The positive ion is attracted to the negative ion, creating a strong electrostatic force that holds the ions together. This attraction occurs due to the difference in charges between the ions, with one ion having a positive charge and the other having a negative charge. The opposite charges attract each other, leading to the formation of an ionic bond.
4.
Ionic compounds have:
Correct Answer
C. No electrical charge
Explanation
Ionic compounds have no electrical charge because they are formed by the transfer of electrons between atoms. In an ionic compound, one atom loses electrons to become positively charged (cation), while another atom gains those electrons to become negatively charged (anion). The positive and negative charges cancel each other out, resulting in a compound that has no overall electrical charge.
5.
The symbol Li+ means:
Correct Answer
B. That this lithium ion has 1 positive charge
Explanation
Lithium has 1 valence electron that it will lose when it forms an ionic bond. Losing that electron gives lithium 1 more proton than it has electrons. This gives it a charge of +1.
6.
NaCl is an example of the chemical formula of:
Correct Answer
C. An ionic compound
Explanation
Ionic compounds do not form true molecules.
7.
How many chloride ions are needed to cancel the 2+ charge of magnesium in magnesium chloride?
Correct Answer
B. 2
Explanation
In magnesium chloride, magnesium has a 2+ charge. Chloride ions have a 1- charge. To cancel out the 2+ charge of magnesium, two chloride ions are needed, as each chloride ion has a 1- charge.
8.
Electrons have what kind of charge?
Correct Answer
B. Negative
Explanation
Electrons have a negative charge. This is because electrons are subatomic particles that orbit around the nucleus of an atom, and they carry a negative charge. The opposite charge, positive, is carried by protons, which are also found in the nucleus. Neutrons, on the other hand, have no charge. Therefore, the correct answer is negative.
9.
What is the name given to the outermost electron(s)?
Correct Answer
C. valence electrons
Explanation
The outermost electrons in an atom are called valence electrons. These electrons are located in the outermost energy level or shell of an atom and are involved in chemical bonding and reactions. Valence electrons determine the reactivity and chemical properties of an element, as they are responsible for forming bonds with other atoms to achieve a stable electron configuration.
10.
When an electron is added to or removed from an atom, the atom becomes a(n) ________.
Correct Answer
A. Ion
Explanation
When an electron is added to or removed from an atom, the atom becomes an ion. An ion is an atom that has gained or lost one or more electrons, resulting in a positive or negative charge. This process occurs when the atom either gains an electron and becomes negatively charged (anion) or loses an electron and becomes positively charged (cation). Ions play a crucial role in chemical reactions and the formation of compounds.
11.
The process of removing or adding electrons is called __________.
Correct Answer
B. Ionization
Explanation
Ionization is the correct answer because it refers to the process of removing or adding electrons from an atom or molecule, resulting in the formation of ions. This process can occur through various means such as heat, light, or chemical reactions. Ionization is an important concept in chemistry and physics, as it plays a crucial role in understanding the behavior of atoms and molecules in various contexts.