Which of the following is correct regarding the pH scale?
A. A substance with a pH of 3 is two times more alkaline than a substance with a pH of 4.
B. A substance with a pH of 3 is 10 times more alkaline than a substance with a pH of 4.
C. A substance with a pH of 3 is two times more acidic than a substance with a pH of 4.
D. A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4.
The correct answer is d. A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4. 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 substance with a pH of 3 has a hydrogen-ion concentration that is 10 times greater than that of a substance with a pH of 4.
A. A substance with a pH of 3 is not two times more alkaline than a substance with a pH of 4.
B. A substance with a pH of 3 is not 10 times more alkaline than a substance with a pH of 4.
C. A substance with a pH of 3 is not two times more acidic than a substance with a pH of 4.
Therefore, the Correct Answer is D.
More Questions on TEAS 7 Science
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Q #1: The covalent bonds between the monomers of an enzyme macromolecule are:
A. Ester bonds
B. Peptide bonds
C. Phosphodiester bonds
D. Glycosidic bonds
Answer Explanation
The correct answer is b. Peptide bonds. Enzymes are proteins, and proteins are made up of amino acid monomers linked together by peptide bonds. A peptide bond is a covalent bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid.
a. Ester bonds are covalent bonds that form between a carboxylic acid and an alcohol.
c. Phosphodiester bonds are covalent bonds that form between a phosphate group and two hydroxyl
groups.
d. Glycosidic bonds are covalent bonds that form between two monosaccharides.
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Q #2: Genetic information describing the characteristics of an organism is found in which of the following?
A. Nuclei
B. Membranes
C. Cilia
D. Ribosomes
Answer Explanation
The correct answer is a. Nuclei. Genetic information describing the characteristics of an organism is found in the nuclei of its cells. The nucleus contains the organism's DNA, which carries the genetic information that determines its traits.
b. Membranes are structures that surround and enclose cells and organelles, but they do not contain genetic information.
c. Cilia are hair-like structures that protrude from the surface of some cells and are involved in movement, but they do not contain genetic information.
d. Ribosomes are organelles that are involved in protein synthesis, but they do not contain genetic information.
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Q #3: Which of the following immune system molecules creates holes in the cell membranes of their target cells in order to destroy the cell?
A. Perforins
B. Interferons
C. Cytokines
D. Lymphotoxins
Answer Explanation
Perforins are immune system molecules that create holes in the cell membranes of their target cells in order to destroy the cell. Perforins are proteins that are released by cytotoxic T cells and natural killer cells
They form pores in the target cell membrane, allowing water and ions to enter the cell and causing it to swell and burst.
The other options are not correct because they do not accurately describe the immune system molecules that create holes in the cell membranes of their target cells. Interferons, cytokines, and lymphotoxins do not create holes in cell membranes.
