What is the chemical formula for water?
A. H2O
B. CO2
C. NaCl
D. C6H12O6
The chemical formula for water is H2O. It consists of two hydrogen atoms and one oxygen atom.
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Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: What is the difference between a solid and a liquid?
A. Solids have a definite shape and volume while liquids have a definite volume but no fixed shape.
B. Solids have no definite shape or volume while liquids have a definite volume and take the shape of their container.
C. Solids and liquids have the same physical properties.
D. Solids have a definite volume but take the shape of their container while liquids have a definite shape and volume.
Answer Explanation
The main difference between a solid and a liquid is their physical state and the way their particles are arranged. In a solid, the particles are tightly packed together and have a fixed position, which gives the solid a definite shape and volume. Solids are also characterized by their high density, low compressibility, and high thermal conductivity.
In contrast, the particles in a liquid are more loosely packed and can move around each other, which allows the liquid to take the shape of its container. Liquids have a definite volume but no fixed shape, which means they can be poured or spilled. Liquids also have a lower density than solids, are more compressible than solids, and have lower thermal conductivity than solids.
Option b) is incorrect because it describes the properties of a gas, not a liquid. Option c) is incorrect because solids and liquids have different physical properties. Option d) is incorrect because it describes the properties of a gas, not a liquid or a solid.
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Q #2: Which of the following describes the process of osmosis?
A. Movement of substances from an area of high concentration to an area of low concentration.
B. Movement of substances against a concentration gradient with the help of transport proteins.
C. Movement of water molecules from an area of high concentration to an area of low concentration through a selectively permeable membrane.
D. Movement of substances into a cell by engulfing them with the plasma membrane.
Answer Explanation
Osmosis is the process by which water molecules move across a selectively permeable membrane from an area of high concentration to an area of low concentration, in order to equalize the concentration of solutes on both sides of the membrane. Selectively permeable membranes allow only certain molecules to pass through, while preventing the passage of others.
In osmosis, the movement of water molecules is driven by the concentration gradient of solutes, which cannot pass through the membrane. If one side of the membrane has a higher concentration of solutes than the other, water molecules will move from the side with the lower concentration of solutes to the side with the higher concentration of solutes, in an atempt to dilute the solutes and equalize the concentration on both sides.
Osmosis is important in many biological processes, including the uptake of water by plant roots, the regulation of water balance in animal cells, and the preservation of food by adding salt or sugar to create a hypertonic environment that inhibits bacterial growth.
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Q #3: Which of the following is the process by which DNA is copied into RNA?
A. Replication
B. Transcription
C. Translation
D. Mutation
Answer Explanation
Transcription is the process by which DNA is copied into RNA. During transcription, the DNA molecule unwinds and RNA polymerase reads the DNA sequence and synthesizes a complementary RNA molecule using the DNA as a template.
