Nursing Elites

1. What is the role of a catalyst in a chemical reaction?

• A. Slows down the reaction
• B. Has no effect
• C. Speeds up the reaction
• D. Stops the reaction

Correct answer: C

Rationale: A catalyst speeds up a chemical reaction by lowering the activation energy required for the reaction to occur. It does not get consumed in the reaction and remains unchanged at the end, allowing it to facilitate multiple reaction cycles. Choice A is incorrect because a catalyst actually speeds up the reaction. Choice B is incorrect because catalysts do have an effect by accelerating the reaction. Choice D is incorrect because catalysts do not stop the reaction, but rather increase the reaction rate.

2. What number represents the number of protons an element has?

• A. Atomic mass
• B. Mass number
• C. Atomic number
• D. Neutron number

Correct answer: C

Rationale: The correct answer is C, atomic number. The atomic number corresponds to the number of protons in an element. This number is unique to each element and determines its placement on the periodic table. It is equal to the number of protons found in the nucleus of an atom of that element. Choice A, atomic mass, represents the average mass of an element's isotopes. Choice B, mass number, is the sum of protons and neutrons in an atom. Choice D, neutron number, specifically refers to the count of neutrons in an atom and not protons.

3. 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.

4. Which of the following best describes an endothermic reaction?

• A. A reaction that absorbs heat
• B. A reaction that releases heat
• C. A reaction that does not involve heat
• D. A reaction that remains at a constant temperature

Correct answer: A

Rationale: An endothermic reaction is a process that absorbs heat from its surroundings. When a reaction absorbs heat, it leads to a decrease in the temperature of the surroundings, making choice A the correct description. In an endothermic reaction, energy is taken in from the surroundings, resulting in a decrease in temperature around the reaction site. Choice B is incorrect because a reaction that releases heat is known as an exothermic reaction. Choice C is incorrect as all reactions involve heat to some extent. Choice D is incorrect as an endothermic reaction does not remain at a constant temperature but rather absorbs heat, leading to a temperature decrease in the surroundings.

5. What creates a dipole in a covalent bond?

• A. Unequal sharing of electrons
• B. Equal sharing of electrons
• C. Exchange of electrons
• D. Transfer of electrons

Correct answer: A

Rationale: A dipole is created in a covalent bond when there is an unequal sharing of electrons between the atoms involved. This results in a partial positive charge on one atom and a partial negative charge on the other, leading to a separation of charges and the formation of a dipole. Choices B, C, and D are incorrect because a dipole is specifically formed due to unequal sharing of electrons, not equal sharing, exchange, or transfer of electrons in a covalent bond.

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