what type of reactions take place in the nucleus to obtain stable nuclear configurations

HESI A2

Chemistry HESI A2 Quizlet

1. What type of reactions take place in the nucleus to achieve stable nuclear configurations?

A. Chemical
B. Nuclear
C. Physical
D. Mechanical

Correct answer: B

Rationale: Nuclear reactions occur within the nucleus to achieve stable nuclear configurations. These reactions involve changes in the composition of atomic nuclei, leading to the formation of more stable elements. Chemical reactions occur in the electron cloud surrounding the nucleus, while physical and mechanical processes do not directly impact the stability of nuclear configurations. Therefore, the correct answer is 'Nuclear.'

2. Which two functional groups would you expect an amino acid to contain?

A. R-NH2 and R-COOH
B. R-CHO and R-CO-NH
C. R-OH and R-COOR
D. R-O-R and R-COOH

Correct answer: A

Rationale: Amino acids are organic compounds that are characterized by the presence of an amino group (NH2) and a carboxylic acid group (COOH) in their chemical structure. These two functional groups, found in option A, are fundamental components of amino acids and play crucial roles in their classification and biological functions. Option B contains an aldehyde group (CHO) and an amide group (CO-NH), which are not characteristic functional groups of amino acids. Option C includes a hydroxyl group (OH) and an ester group (COOR), which are not typically present in amino acids. Option D presents ether (R-O-R) and carboxylic acid (COOH) functional groups, which do not represent the functional groups commonly found in amino acids.

3. What is the oxidation state of the sulfur atom in sulfuric acid H2SO4?

A. 4
B. 6
C. 8
D. 10

Correct answer: B

Rationale: In sulfuric acid (H2SO4), sulfur has an oxidation state of +6. The oxidation state is determined by considering the overall charge of the compound and the known oxidation states of other elements. In this case, hydrogen is typically +1, and oxygen is -2. To balance the charges and match the compound's overall charge of 0, sulfur must have an oxidation state of +6. Choice A (4) is incorrect because it doesn't balance the charges in the compound. Choices C (8) and D (10) are also incorrect as they are not valid oxidation states for sulfur in this compound.

4. What is the correct electron configuration for carbon?

A. 1sÂ²2sÂ²2pÂ¹
B. 1sÂ²2sÂ²2pÂ²
C. 1sÂ²2sÂ²2pÂ³
D. 1sÂ²2sÂ²2pâ¶3sÂ¹

Correct answer: B

Rationale: The correct electron configuration for carbon is 1sÂ²2sÂ²2pÂ². This configuration indicates that there are 2 electrons in the first energy level (1sÂ²), 2 electrons in the second energy level (2sÂ²), and 2 electrons in the second energy level (2pÂ²). It adheres to the aufbau principle, which states that electrons fill orbitals starting from the lowest energy level, and the Pauli exclusion principle, which states that each electron in an atom must have a unique set of quantum numbers. Choice A is incorrect because it does not fill the 2p orbital correctly. Choice C is incorrect as it exceeds the number of possible electrons in the 2p orbital. Choice D is incorrect as it includes an electron in the 3s orbital, which is not part of the electron configuration for carbon.

5. How many neutrons are in an atom of uranium-235?

A. 92
B. 125
C. 143
D. 235

Correct answer: A

Rationale: The correct answer is A: '92'. To determine the number of neutrons in an atom, you subtract the atomic number (number of protons) from the atomic mass number. For uranium-235, the atomic number is 92, and the atomic mass number is 235. Subtracting 92 from 235 gives us 143 neutrons in an atom of uranium-235. Therefore, options B, C, and D are incorrect as they do not represent the correct number of neutrons in an atom of uranium-235.