what type of radiation is high energy electromagnetic radiation that lacks charge and mass

HESI A2

Chemistry HESI A2 Quizlet

1. 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.

2. How many electron pairs are shared to form a double covalent bond?

A. 1
B. 2
C. 3
D. 4

Correct answer: B

Rationale: The correct answer is B. In a double covalent bond, two pairs of electrons are shared between two atoms. This sharing of two electron pairs results in a stronger bond compared to a single covalent bond where only one pair of electrons is shared. Choice A is incorrect because a single covalent bond involves the sharing of one pair of electrons. Choices C and D are incorrect as they do not represent the correct number of electron pairs shared in a double covalent bond.

3. What is the boiling point of water in Â°C?

A. 90Â°C
B. 100Â°C
C. 95Â°C
D. 80Â°C

Correct answer: B

Rationale: The correct answer is 100Â°C. The boiling point of water in Celsius is 100Â°C, which is standard at sea level. This is the temperature at which water changes from a liquid to a gas phase under standard atmospheric pressure. Choice A (90Â°C), Choice C (95Â°C), and Choice D (80Â°C) are incorrect because they do not represent the standard boiling point of water at sea level.

4. Among the following elements, which is a nonmetal?

A. Mercury
B. Magnesium
C. Sulfur
D. Potassium

Correct answer: C

Rationale: Sulfur is a nonmetal as it is located on the right side of the periodic table. Nonmetals generally exhibit properties such as being brittle, poor conductors of heat and electricity, and having lower melting points compared to metals. Mercury (A), Magnesium (B), and Potassium (D) are all metals due to their metallic properties. Mercury is a liquid metal at room temperature, Magnesium is a solid metal, and Potassium is a solid metal as well. Therefore, the correct answer is C, Sulfur.

5. What effect does increasing the surface area of a reactant have?

A. Decreases the reaction rate
B. Has no effect
C. Increases the reaction rate
D. Stops the reaction

Correct answer: C

Rationale: Increasing the surface area of a reactant leads to more particles being exposed to the reaction, which in turn increases the reaction rate. This is because a larger surface area provides more sites for collisions between reacting particles, resulting in a higher frequency of successful collisions and thus accelerating the reaction. Choice A, 'Decreases the reaction rate,' is incorrect because increasing surface area actually accelerates the reaction. Choice B, 'Has no effect,' is incorrect as increasing surface area does have a significant effect on the reaction rate. Choice D, 'Stops the reaction,' is incorrect as increasing surface area does not stop the reaction but rather enhances it.