which of the following is a balanced chemical equation

ATI TEAS 7

ati teas 7 science

1. Which of the following is a balanced chemical equation?

A. H2 + O2 â†’ H2O
B. 2H2 + O2 â†’ 2H2O
C. 3H2O â†’ 2H2 + O2
D. H2O â†’ H2 + O2

Correct answer: B

Rationale: A balanced chemical equation must have the same number of atoms of each element on both sides of the equation. In option B, 2H2 + O2 â†’ 2H2O, the equation is balanced as there are 2 hydrogen atoms and 2 oxygen atoms on both the reactant and product sides after balancing, satisfying the law of conservation of mass. Option A is unbalanced as there are 2 oxygen atoms on the reactant side but only 1 oxygen atom on the product side. Option C is unbalanced with 3 hydrogen atoms on the reactant side and 2 hydrogen atoms on the product side. Option D is unbalanced with 1 oxygen atom on the reactant side and 2 oxygen atoms on the product side.

2. What is the tough, fibrous connective tissue that attaches muscle to bone?

A. Fascia
B. Perimysium
C. Tendon
D. Ligament

Correct answer: C

Rationale: Tendons are the correct answer as they are the tough, fibrous connective tissues that attach muscle to bone. They play a crucial role in transmitting the forces generated by muscle contraction to the bones, facilitating movement. Fascia surrounds muscles and provides support, perimysium is the connective tissue sheath around muscle fibers, and ligaments connect bone to bone, stabilizing joints, which makes them distinct from tendons.

3. Which type of cartilage allows for smooth movement at joints and absorbs shock?

A. Hyaline cartilage
B. Fibrocartilage
C. Elastic cartilage
D. None of the above

Correct answer: B

Rationale: Fibrocartilage is the correct answer. It is found in areas requiring both support and resilience, such as the intervertebral discs and knee joints. Fibrocartilage contains collagen fibers for strength and proteoglycans for resilience, making it suitable for functions that involve smooth movement at joints and shock absorption. Hyaline cartilage, while providing structural support, is not primarily responsible for smooth movement and shock absorption. Elastic cartilage is more flexible and is found in locations like the ear and epiglottis, but it is not known for its shock-absorbing properties. Choosing 'None of the above' disregards the correct option of fibrocartilage, which is specifically designed for the functions described in the question.

4. What is the periodic law?

A. The statement that the properties of the elements are a periodic function of their atomic numbers.
B. The statement that elements can be arranged in a table where elements with similar properties are grouped together.
C. The statement that elements can be arranged in a table where the atomic number of an element is equal to the number of protons in its nucleus.
D. The statement that elements can be arranged in a table where the atomic mass of an element is equal to the number of neutrons in its nucleus.

Correct answer: A

Rationale: The periodic law states that the properties of elements are a periodic function of their atomic numbers. This means that when elements are arranged in order of increasing atomic number, there is a periodic repetition of their properties. This forms the basis for the modern periodic table. Option B describes the organization of elements in the periodic table, which is related to the periodic law but not the definition of it. Options C and D are incorrect as they describe concepts related to atomic structure (atomic number and atomic mass) rather than the periodic law itself.

5. Which blood vessels carry oxygenated blood from the heart to the rest of the body?

A. Pulmonary arteries
B. Pulmonary veins
C. Systemic arteries
D. Systemic veins

Correct answer: C

Rationale: The correct answer is systemic arteries. Systemic arteries carry oxygenated blood from the heart to the rest of the body to provide oxygen and nutrients to tissues. Pulmonary arteries carry deoxygenated blood from the heart to the lungs for oxygenation. Pulmonary veins transport oxygenated blood from the lungs back to the heart. Systemic veins return deoxygenated blood from the body tissues to the heart for reoxygenation. Therefore, choices A, B, and D are incorrect as they do not carry oxygenated blood away from the heart to the body.