if oxygen is in a compound what would its oxidation number be

HESI A2

HESI A2 Chemistry Practice Test

1. If oxygen is in a compound, what would its oxidation number be?

A. 2
B. -2
C. 0
D. -1

Correct answer: B

Rationale: Oxygen typically has an oxidation number of -2 in compounds because it tends to gain electrons. This is due to its high electronegativity, which leads to oxygen attracting electrons towards itself in a chemical bond. Choice A (2) is incorrect because oxygen doesn't have a +2 oxidation number in compounds. Choice C (0) is incorrect as oxygen rarely has an oxidation number of 0 in compounds. Choice D (-1) is incorrect as oxygen's oxidation number in compounds is typically -2, not -1.

2. What type of radiation is high-energy electromagnetic radiation that lacks charge and mass?

A. Beta
B. Alpha
C. Gamma
D. Delta

Correct answer: C

Rationale: Gamma radiation is a form of high-energy electromagnetic radiation that does not possess charge or mass. This type of radiation is commonly used in various fields due to its penetrating ability and lack of charge or mass, making it different from alpha and beta radiation, which consist of charged particles. Therefore, the correct answer is C - Gamma. Choices A and B are incorrect as they refer to alpha and beta radiation, which are composed of charged particles. Choice D, Delta, is not a type of radiation.

3. How many electrons are in a neutral atom of neon?

A. 9
B. 10
C. 11
D. 12

Correct answer: B

Rationale: The atomic number of neon is 10, which represents the number of protons in its nucleus. In a neutral atom, the number of electrons is equal to the number of protons to maintain electrical neutrality. Therefore, a neutral atom of neon contains 10 electrons, matching the 10 protons within the nucleus. Choice A (9 electrons) is incorrect as it doesn't correspond to the atomic number of neon. Choices C (11 electrons) and D (12 electrons) are also incorrect as they do not align with the correct atomic number of neon.

4. What are proteins made up of?

A. Fatty acids
B. Amino acids
C. Nucleotides
D. Sugars

Correct answer: B

Rationale: Proteins are made up of amino acids. Amino acids are the building blocks of proteins, essential for various biological processes in the body such as enzyme function, transport, and structural support. Fatty acids (Choice A) are components of lipids, not proteins. Nucleotides (Choice C) are the building blocks of nucleic acids like DNA and RNA, not proteins. Sugars (Choice D) are carbohydrates and are not the primary components of proteins.

5. Beta radiation is the product of the decomposition of which particle?

A. Proton
B. Neutron
C. Electron
D. Photon

Correct answer: B

Rationale: Beta radiation is the result of the decomposition of a neutron. During beta decay, a neutron in an atom's nucleus is transformed into a proton, an electron (beta particle), and an antineutrino. Therefore, the correct answer is 'Neutron.' Choice A, 'Proton,' is incorrect because beta decay does not involve the decomposition of a proton. Choice C, 'Electron,' is incorrect because electrons are actually produced during beta decay. Choice D, 'Photon,' is incorrect as beta radiation does not involve the decomposition of photons.