1.
What type of atoms (or ions) will form an ionic substance?
Correct Answer
C. A metal ion and a non-metal ion
Explanation
An ionic substance is formed when a metal ion and a non-metal ion combine. This is because metals tend to lose electrons and become positively charged ions, while non-metals tend to gain electrons and become negatively charged ions. The attraction between the oppositely charged ions results in the formation of an ionic bond, creating an ionic substance.
2.
What do the subscripts mean in a chemical formula? Example H2O
Correct Answer
B. The subscript indicates the number of atoms of each type that form the substance
Explanation
The subscripts in a chemical formula, such as H2O, indicate the number of atoms of each type that form the substance. In this example, H2O means that there are two hydrogen atoms and one oxygen atom in a molecule of water. Subscripts are used to accurately represent the composition of a compound and the ratio of different elements present in it.
3.
What type of ion do metals form?
Correct Answer
A. Metals form positive cations. Example Na 1+
Explanation
Metals form positive cations because they tend to lose electrons during chemical reactions, resulting in a positive charge. This is due to the fact that metals have low ionization energies and low electronegativities, making it easier for them to give up electrons and become positively charged ions. The example given, Na 1+, represents sodium (Na) losing one electron to form a sodium ion with a positive charge.
4.
Why are there 2 hydrogen and only 1 oxygen in water (H2O)?
Correct Answer
A. Each hydrogen ion has a charge of 1+. This will balance the charge of 2- from the one oxygen ion
Explanation
The correct answer explains that each hydrogen ion has a charge of 1+, which balances the charge of 2- from the one oxygen ion. This means that two hydrogen ions are needed to balance the charge of one oxygen ion in order to form a stable water molecule.
5.
What type of bonds do salts form?
Correct Answer
B. Salts are made up of a metal and non-metal and form an ionic bond.
Explanation
Salts are compounds formed when a metal reacts with a non-metal. In this reaction, the metal atom loses electrons to form a positively charged ion, while the non-metal atom gains those electrons to form a negatively charged ion. These oppositely charged ions are held together by strong electrostatic forces, forming an ionic bond. Therefore, salts are made up of a metal and non-metal and form an ionic bond.
6.
Compare the strength of an ionic bond to that of a covalent bond.
Correct Answer
A. An ionic bond is very strong and therefore the substance will have a high melting and boiling point.
Explanation
Ionic bonds are formed between ions with opposite charges, typically a metal and a nonmetal. These bonds are formed through the transfer of electrons from one atom to another. The resulting electrostatic attraction between the ions is very strong, leading to a high melting and boiling point for substances with ionic bonds. This is because a large amount of energy is required to break the strong electrostatic forces holding the ions together. Therefore, the given answer correctly states that an ionic bond is very strong and results in a substance with a high melting and boiling point.
7.
Which of the following is the correct name for MgCl2?
Correct Answer
A. Magnesium chloride
Explanation
The correct name for MgCl2 is Magnesium chloride. The compound consists of one magnesium ion (Mg2+) and two chloride ions (Cl-), so the name reflects the combination of these elements. The Roman numeral is not necessary in this case because magnesium only forms one type of ion.
8.
What is the correct name for FeBr3?
Correct Answer
B. Iron (III) bromide
Explanation
The correct name for FeBr3 is Iron (III) bromide. This is because FeBr3 is a compound made up of iron and bromine, and the Roman numeral III indicates that iron has a charge of +3 in this compound. Therefore, Iron (III) bromide is the appropriate name for FeBr3.
9.
What is correct formula for Calcium ion combined with a phosphate ion?
Correct Answer
A. Ca3(PO4)2
Explanation
Calcium will form an ion with a 2+ charge.
Phosphate is PO4 and will form an ion with a 3- charge.
10.
What is the chemical formula for Potassium sulfate?
Correct Answer
C. K2SO4
Explanation
The chemical formula for Potassium sulfate is K2SO4. This is because Potassium has a charge of +1 and sulfate has a charge of -2. To balance the charges, two potassium ions are needed to combine with one sulfate ion, resulting in the formula K2SO4.