when sugar is heated it breaks down into carbon and water vapor this is an example of a

ATI TEAS 7

TEAS 7 science quizlet

1. When sugar is heated, it breaks down into carbon and water vapor. This is an example of a:

A. Combination reaction
B. Decomposition reaction
C. Double displacement reaction
D. Single displacement reaction

Correct answer: B

Rationale: The correct answer is B: Decomposition reaction. When sugar is heated, it undergoes a decomposition reaction where it breaks down into simpler substances, carbon, and water vapor. In a decomposition reaction, a single compound breaks down into two or more simpler substances. This process is the opposite of a combination reaction where two or more substances combine to form a new compound. Choice A, Combination reaction, is incorrect because a combination reaction involves the combination of two or more substances to form a new compound, which is the opposite of what happens when sugar breaks down. Choices C and D, Double displacement reaction and Single displacement reaction, are incorrect as they involve different mechanisms where the atoms or ions of the reactants are exchanged, which is not the case in the breakdown of sugar into carbon and water vapor.

2. What is the median of Pernell's scores (81, 92, 87, 89, and 94)?

A. 87
B. 89
C. 92
D. 94

Correct answer: B

Rationale: To find the median, we first need to arrange the scores in ascending order: 81, 87, 89, 92, 94. Since there are five scores, the middle score would be the third one, which is 89. Hence, the median of Pernell's scores is 89. Choice A (87) is incorrect because it is the second score in the ordered list, not the middle one. Choice C (92) and Choice D (94) are also incorrect as they are not positioned in the middle of the ordered series.

3. Which of the following movie titles contains a pronoun?

A. Rear Window
B. North by Northwest
C. The Trouble with Harry
D. The Man Who Knew Too Much

Correct answer: D

Rationale: The title "The Man Who Knew Too Much" contains the pronoun "who."

4. Which valve prevents backflow into the atrium when the ventricles contract?

A. Pulmonary valve
B. Tricuspid valve
C. Mitral valve
D. Aortic valve

Correct answer: B

Rationale: The tricuspid valve (right atrioventricular valve) prevents backflow into the right atrium when the right ventricle contracts. This valve ensures that blood flows in the correct direction, preventing regurgitation into the atrium. The pulmonary valve is responsible for preventing backflow into the right ventricle from the pulmonary artery. The mitral valve prevents backflow into the left atrium, and the aortic valve prevents backflow into the left ventricle from the aorta. Therefore, the correct answer is the tricuspid valve as it specifically addresses the scenario of backflow into the atrium during ventricular contraction.