Answer the following question given this paragraph: When chemists synthesize a new compound, they may not yet know its molecular or structural formula. In such cases, they usually begin by determining itsempirical formula, the relative numbers of atoms of the elements in a compound, reduced to the smallest whole numbers. Because the empirical formula is based on experimental measurements of the numbers of atoms in a sample of the compound, it shows only the ratios of the numbers of the elements present. The difference betweenempirical and molecular formulas can be illustrated with butane, a covalent compound used as the fuel in disposable lighters. The molecular formula for butane is C4H10. The ratio of carbon atoms to hydrogen atoms in butane is 4:10, which can be reduced to 2:5. The empirical formula for butane is therefore C2H5. The formula unit is the absolutegrouping of atoms or ions represented by the empirical formula of a compound, either ionic or covalent. Butane, for example, has the empirical formula C2H5, but it contains two C2H5 formula units, giving a molecular formula of C4H10. Because ionic compounds do not contain discrete molecules, empirical formulas are used to indicate their compositions. All compounds, whether ionic or covalent, must be electrically neutral. Consequently, the positive and negative charges in a formula unit must exactly cancel each other. If the cation and the anion have charges of equal. Q: All compounds, whether ionic or covalent, must be what? Choices: - abnormal neutral - organic neutral - metallic neutral - electrically neutral A:
electrically neutral
(Question)
Answer the following question given this paragraph: Tremetol, a metabolic poison found in the white snake root plant, prevents the metabolism of lactate. When cows eat this plant, it is concentrated in the milk they produce. Humans who consume the milk become ill. Symptoms of this disease, which include vomiting, abdominal pain, and tremors, become worse after exercise. Why do you think this is the case? Alcohol Fermentation Another familiar fermentation process is alcohol fermentation ( Figure 7.15) that produces ethanol, an alcohol. The first chemical reaction of alcohol fermentation is the following (CO2 does not participate in the second reaction):. Q: Tremetol, a metabolic poison found in the white snake root plant, prevents the metabolism of what? Choices: - sugars - sodium - lipids - lactate A:
(Answer)
lactate
Ques: Answer the following question given this paragraph: The active transport of ions across the cell membrane causes an electrical gradient to build up across this membrane. The number of positively charged ions outside the cell is usually greater than the number of positively charged ions in the cytosol. This results in a relatively negative charge on the inside of the membrane, and a positive charge on the outside. This difference in charges causes a voltage to exist across the membrane. Voltage is electrical potential energy that is caused by a separation of opposite charges, in this case across the membrane. The voltage across a membrane is the membrane potential . Membrane potential is very important for the conduction of electrical impulses along nerve cells. The membrane potential of a cell at rest is known as its resting potential , and is discussed below. A non-excited nerve cell is an example of a cell at rest. Q: What causes a voltage to exist across the membrane in cells? Choices: - insulators - increase in energy - same charge - difference in charges A:
Ans: difference in charges
(Q).
Answer the following question given this paragraph: After you eat and digest a sugary snack, the level of sugar in your blood quickly rises. In response, the endocrine system secretes the hormone insulin. Insulin helps cells absorb sugar from the blood. This causes the level of sugar in the blood to fall back to its normal level. Q: What hormone does the endocrine system secrete to help cells absorb blood sugar? Choices: - glucose - testosterone - Cortisol - insulin A:
(A).
insulin
Ques:Answer the following question given this paragraph: Many meteorites are remnants of the earliest material that formed in the solar system. Q: What astronomical phenomenon is often comprised of remnants of the earliest material that formed in the solar system? Choices: - asteroids - particles - comets - meteorites A:

Ans:meteorites
Ques: Answer the following question given this paragraph: Contour lines are lines of equal elevation. Contour intervals are the difference in elevation between two contour lines. Q: What is the term for the difference in elevation between two contour lines? Choices: - height - design interval - mapping interval - contour interval A:
Ans:
contour interval