HESI A2 Practice Test 3 Chemistry

D. Because this is a positive correlation, if the nutrient concentration increases or decreases, plant height will either increase or decrease accordingly. See Lesson: Designing an Experiment.

B. Gram is the metric base unit for mass. See Lesson: Designing an Experiment.

A. All choices are written in scientific notation and have negative exponents, which means the decimal place moves to the left when converting to standard notation. Because its decimal place moves to the left more spaces than the others, answer A has the smallest magnitude. See Lesson: Scientific Notation.

D. Silicon shares eight electrons, which is more than any of the others share. Phosphorus shares six electrons, oxygen shares four electrons, and each chlorine atom shares two electrons. See Lesson: Chemical Bonds.

D. Celsius can be converted to Kelvin by adding 273 to the Celsius value. In this case, 273 added to 189°C yields 462 K. See Lesson: Temperature and the Metric System.

C. None of the properties listed indicate a chemical change, so they are physical properties. See Lesson: Properties of Matter.

B. Celsius is one of three temperature scales and the only one that belongs to the metric system. It can be converted to Kelvin using 273. See Lesson: Temperature and the Metric System.

A. The products are present at the end of the reaction (C + D). The relative energy of these products is 20 kJ, which is lower than all other species in the reaction. See Lesson: Chemical Solutions.

B. Because the exponent is negative, the decimal point moves to the left when converting to standard notation. After moving one space, it is on the other side of the 1. It moves eight more spaces to the left, and the spaces are filled in with zeros. See Lesson: Scientific Notation.

C. Because the 2 comes after the symbol for silver (Ag), it shows how many silver atoms are in one particle of the compound. See Lesson: Chemical Bonds.

A. The weight of fish is the dependent variable because it is dependent on how much food is supplied to each fish tank over the four-week period. See Lesson: Designing an Experiment.

C. In the cooling curve, the melting point is where the second plateau in temperature occurs, which is around 1700°C. See Lesson: States of Matter.

B. When hydroxide ions (OH^-) from a base react with hydrogen ions from an acid, both water and salt are formed. See Lesson: Acids and Bases.

B. As the butter melts, it goes from a solid to a liquid, which takes the shape but not the volume of its container. See Lesson: States of Matter.

A. The amount of energy released is the difference in energy between the reactants and the products. Overall, the reactants released 10 kJ to get from 30 kJ to 20 kJ in the products. See Lesson: Chemical Solutions.

B. Fluorine and bromine are the only pair located in the same group (column) of the periodic table, group 17. See Lesson: Scientific Notation.

C. When acetic acid dissolves in water, it forms an aqueous solution that contains hydronium ions and acetate ions (CH₃COO-). See Lesson: Acids and Bases.

C. In the metric system, the multiplying factor of 106 corresponds to a metric prefix of mega-. This means there are 1,000,000 grams in one megagram. See Lesson: Temperature and the Metric System.

A. Because silicon and oxygen are both nonmetals, they will share electrons, forming a covalent bond. See Lesson: Chemical Bonds.

C. Because the researcher is studying the effects of sunlight on plant growth and sunlight radiates heat to the plant, she should use a thermometer to measure temperature. See Lesson: Designing an Experiment.

C. Families in the periodic table are associated with groups (columns). Strontium is the only element listed that is in group 2 with calcium. See Lesson: Scientific Notation.

C. Intensive properties do not depend on the amount of matter that is present. See Lesson: Properties of Matter.

D. Between 20 and 30 minutes, the temperature is constant, which means there is a phase change occurring. Since this is the second phase change of a cooling curve, the substance must be freezing. Therefore, the sample is a mixture of solid and liquid. See Lesson: States of Matter.

D. When a Brønsted-Lowry base dissociates in an aqueous solution, it accepts hydrogen ions and increases hydroxide ion concentration. See Lesson: Acids and Bases.