Ques: Answer the following question given this paragraph: To measure very small masses, scientists use electronic balances, like the one in the Figure below . This type of balance also makes it easier to make accurate measurements because mass is shown as a digital readout. In the picture, the balance is being used to measure the mass of a white powder on a plastic weighing tray. The mass of the tray alone would have to be measured first and then subtracted from the mass of the tray and powder together. The difference between the two masses is the mass of the powder alone. Q: What instrument, with a digital readout, is used by scientists to measure very small masses? Choices: - mixed balance - mechanical balance - common balance - electronic balance A:
Ans: electronic balance

Ques: Answer the following question given this paragraph: A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the population's gene pool . For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. Q: All the genes in all the members of a population make up its what? Choices: - phenotype - diversity - longevity - gene pool A:
Ans: gene pool

Ques: Answer the following question given this paragraph: Liquefaction of Gases Liquefaction of gases is the condensation of gases into a liquid form, which is neither anticipated nor explained by the kinetic molecular theory of gases. Both the theory and the ideal gas law predict that gases compressed to very high pressures and cooled to very low temperatures should still behave like gases, albeit cold, dense ones. As gases are compressed and cooled, however, they invariably condense to form liquids, although very low temperatures are needed to liquefy light elements such as helium (for He, 4.2 K at 1 atm pressure). Liquefaction can be viewed as an extreme deviation from ideal gas behavior. It occurs when the molecules of a gas are cooled to the point where they no longer possess sufficient kinetic energy to overcome intermolecular attractive forces. The precise combination of temperature and pressure needed to liquefy a gas depends strongly on its molar mass and structure, with heavier and more complex molecules usually liquefying at higher temperatures. In general, substances with large van der Waals acoefficients are relatively easy to liquefy because large a coefficients indicate relatively strong intermolecular attractive interactions. Conversely, small molecules with only light elements have small a coefficients, indicating weak intermolecular interactions, and they are relatively difficult to liquefy. Gas liquefaction is used on a massive scale to separate O2, N2, Ar, Ne, Kr, and Xe. After a sample of air is liquefied, the mixture is. Q: Liquefaction ccurs when the molecules of a gas are cooled to the point where they no longer possess sufficient kinetic energy to overcome what? Choices: - intermolecular gravitational forces - gravitational attractive forces - bonding attractive forces - intermolecular attractive forces A:
Ans: intermolecular attractive forces

Ques: Answer the following question given this paragraph: In deductive reasoning, I make a specific prediction based on a general principle. One general principle is that acids turn blue litmus paper red. If I have a bottle of liquid labeled "acid," I expect the litmus paper to turn red when I immerse it in the liquid. Q: Making a specific prediction based on a general principle is known as what type of reasoning? Choices: - common sense reasoning - logical reasoning - validating reasoning - deductive reasoning A:
Ans:
deductive reasoning