For which of the following reasons does a chloride ion have a negative charge?
A. It gained an electron
B. It lost an electron.
C. It lost a proton.
D. It gained a proton.
A chloride ion has a negative charge because it gained an electron. When an atom gains an electron, it becomes negatively charged because it now has more electrons than protons. In the case of a chloride ion, the neutral chlorine atom gains an electron to become a negatively charged chloride ion.
The other options are incorrect because they do not result in a negative charge. Losing an electron would result in a positive charge. Losing or gaining a proton would change the identity of the atom and is not related to the formation of a chloride ion.
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: Which of the following growth curves shows a population that is at its carrying capacity?
A. B
B. C
C. A
D. D
Answer Explanation
A population is said to be at its carrying capacity when it has reached the maximum number of individuals that can be sustained in a particular environment over a prolonged period of time, given the available resources and the prevailing environmental conditions.
In other words, carrying capacity refers to the maximum population size that a given ecosystem can support without being depleted of resources or experiencing environmental degradation. Once a population reaches its carrying capacity, its growth rate slows down and stabilizes, as individuals start to compete more intensely for resources such as food, water, and shelter, and mortality rates increase.
Carrying capacity is an important concept in ecology and population biology because it helps to explain the dynamics of natural populations and how they are influenced by changes in the environment, such as climate change, habitat loss, and human activities.
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Q #2: Which of the following structures is an exocrine gland?
A. Pineal gland
B. Parathyroid gland
C. Parotid gland
D. Pituitary gland
Answer Explanation
The parotid gland is an exocrine gland that secretes saliva into the mouth. Exocrine glands secrete their products into ducts that carry the secretions to the body's surface or into body cavities. The other options are endocrine glands, which secrete hormones directly into the bloodstream. The pineal gland secretes melatonin, the parathyroid glands secrete parathyroid hormone, and the pituitary gland secretes several hormones that regulate various bodily functions.
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Q #3: How many times stronger is the hydrogen-ion concentration of a pH 4 solution as compared with a pH 9 solution?
A. 0.00001
B. 5
C. 100,000
D. 50
Answer Explanation
The correct answer is c. 100,000. The pH scale is a logarithmic scale, which means that each change of one pH unit represents a tenfold change in the hydrogen-ion concentration. A pH 4 solution has a hydrogen-ion concentration that is 10^5 (or 100,000) times greater than that of a pH 9 solution.
a. 0.00001 is the hydrogen-ion concentration of a pH 9 solution as compared with a pH 4 solution.
b. 5 is the difference in pH units between a pH 4 solution and a pH 9 solution.
d. 50 is not the correct answer.
