group ia elements have what charge

HESI A2

Chemistry HESI A2 Quizlet

1. What charge do Group IA elements have?

A. +1
B. +2
C. +3
D. 0

Correct answer: A

Rationale: Group IA elements, also known as alkali metals, have a +1 charge. They readily lose one electron to achieve a stable electron configuration, forming ions with a single positive charge. This makes +1 the correct choice. Choices B, C, and D are incorrect because alkali metals in Group IA typically lose one electron, so they do not have a +2, +3, or 0 charge.

2. What does the mass of one mole of a substance represent?

A. Atomic mass
B. Mass number
C. Molecular weight
D. Molar mass

Correct answer: D

Rationale: The mass of one mole of a substance is represented by its molar mass. Molar mass is the mass of one mole of a substance and is expressed in grams per mole. It is calculated by summing the atomic masses of all atoms in a molecule. Therefore, the correct answer is D - 'Molar mass'. Choice A, 'Atomic mass', refers to the average mass of an atom of an element. Choice B, 'Mass number', is the total number of protons and neutrons in an atom's nucleus. Choice C, 'Molecular weight', is the average mass of a molecule relative to 1/12 of the mass of an atom of carbon-12.

3. What does a blood sample with a pH of 3 indicate?

A. It is strongly acidic.
B. It is strongly basic.
C. It is weakly acidic.
D. It is weakly basic.

Correct answer: A

Rationale: A blood pH of 3 is significantly low, indicating a strong acidity level. The normal blood pH range is 7.35 to 7.45; therefore, a pH of 3 is far below the normal range, showing a highly acidic condition in the blood sample. Choice B is incorrect because a pH of 3 is not basic at all. Choice C is incorrect as a pH of 3 is not weakly acidic but strongly acidic. Choice D is wrong as a blood pH of 3 does not indicate a weakly basic condition.

4. When an acid is added to a base, water and a salt form. What kinds of bonds form in these two compounds?

A. Liquid and metallic
B. Polar and nonpolar covalent
C. Polar covalent and ionic
D. Ionic only

Correct answer: C

Rationale: In water, the bond formed between the oxygen atom and the hydrogen atoms is a polar covalent bond. The oxygen atom attracts the shared electrons more strongly, creating a partial negative charge on the oxygen and a partial positive charge on the hydrogen atoms. In the salt formed, the bond between the metal cation and the nonmetal anion is predominantly an ionic bond. The metal cation donates electrons to the nonmetal anion, resulting in the formation of oppositely charged ions that are held together by electrostatic attractions. Choices A and B are incorrect because water and salts do not form bonds that are liquid and metallic, or polar and nonpolar covalent. Choice D is incorrect as it oversimplifies the types of bonds present in water and salts, failing to differentiate between the covalent bond in water and the ionic bond in the salt.

5. What is matter that has a definite shape and volume?

A. Liquid
B. Solid
C. Gas
D. Plasma

Correct answer: B

Rationale: Matter that has a definite shape and volume is referred to as a solid. Solids maintain their shape and volume under normal conditions, unlike liquids that have a definite volume but take the shape of their container, gases that have neither a definite shape nor volume, and plasma which is a state of matter with no definite shape or volume and consists of charged particles.