Nursing Elites

1. What is the general formula for an alkene?

• A. CnH2n+2
• B. CnH2n
• C. CnH2n-2
• D. CnH2n+1

Correct answer: B

Rationale: The general formula for an alkene is \(C_nH_{2n}\), indicating the presence of a double bond between carbon atoms.

2. What is the mass number of an element?

• A. The number of protons in an atom's nucleus.
• B. The number of neutrons in an atom's nucleus.
• C. The number of electrons in an atom's valence shell.
• D. The number of isotopes of an element.

Correct answer: B

Rationale: The mass number of an element is the total number of protons and neutrons in the nucleus of an atom. It is represented by the symbol A and is written as a superscript to the element's symbol. For example, the mass number of carbon-12 is 12, which means that a carbon-12 atom has 6 protons and 6 neutrons in its nucleus.

3. What is the formula to calculate acceleration?

• A. Acceleration= Mass Force ​
• B. Acceleration= Force Mass ​
• C. Acceleration= Time Distance ​
• D. Acceleration= Time Change in Velocity ​

Correct answer: A

Rationale: Acceleration is calculated as the change in velocity divided by the time taken.

4. In the context of the cardiac cycle, the P wave on an electrocardiogram (ECG) represents:

• A. Atrial depolarization
• B. Ventricular depolarization
• C. Atrial repolarization
• D. Ventricular repolarization

Correct answer: A

Rationale: The correct answer is A: "Atrial depolarization." The P wave on an ECG represents the depolarization of the atria, specifically the spread of electrical activity through the atria causing them to contract and push blood into the ventricles. This is the first wave observed on the ECG and signifies the beginning of the cardiac cycle. Ventricular depolarization is represented by the QRS complex, atrial repolarization is typically not visible on a standard ECG due to its timing with the QRS complex, and ventricular repolarization is represented by the T wave. Therefore, option A is the most appropriate choice in this context.

5. Which of the following is an example of a chemical change?

• A. Dissolving sugar in water
• B. Boiling water
• C. Rusting iron
• D. Crushing ice

Correct answer: C

Rationale: Rusting is a chemical reaction where iron reacts with oxygen and water to form iron oxide (rust).

6. The microscopic units responsible for muscle contraction are called

• A. Neurons
• B. Myofibrils
• C. Tendons
• D. Sarcomeres

Correct answer: D

Rationale: The correct answer is D: Sarcomeres. Sarcomeres are the fundamental contractile units of skeletal muscle. They are composed of overlapping actin and myosin filaments that slide past each other during muscle contraction, resulting in muscle shortening. Neurons (A) are nerve cells that transmit signals to and from the brain. Myofibrils (B) are thread-like structures within muscle fibers that contain sarcomeres. Tendons (C) are fibrous connective tissues that attach muscles to bones, but they are not directly involved in muscle contraction like sarcomeres are.

Similar Questions