Knewton Assessment Exam Questions With Verified Answers

Knewton Assessment Exam Questions With Verified Answers. When 5.0 grams of calcium are burned in oxygen, 7.0 grams of calcium oxide result. What mass of oxygen reacted? - answer2.0 grams Which of the following events fail to follow the law of conservation of matter? Select the correct answer below: Burning wood for a fire Freezing water into ice cubes The decomposition of MgCl2 into Mg and Cl2 None of these - answerNone of these If you boil an entire sample of water, the steam that results will have: - answerthe same mass as the water Through the complete electrolysis of a sample of pure water, a student collects 14.0 grams of hydrogen gas and 112.0 grams of oxygen gas. What mass of water (in grams), if it reacted completely, was initially present? (The electrolysis of water is the use of an electric current to decompose it into its component elements.) - answer126.0 g Which of the following CANNOT be classified as a compound?a. carbon dioxideb. sodium chloridec. lithiumd. sugar - answerc. lithiumLithium is an element. The rest are made of multiple elements. The nucleus of an atom can be split into smaller components by what kind of process? - answernone of the above: a physical or chemical process or melting - The nucleus of an atom cannot be split into its components by either a physical or chemical change. Splitting an atom is a nuclear process. If something is a compound, it is also - answera pure substance - Pure substances are either elements or compounds. A compound is a pure substance composed of more than one element. A compound is a chemical substance composed of two or more kinds of elements in a fixed ratio. By what means can the components of a compound be separated? - answerChemical means - A compound cannot be separated into its component elements by physical means, but it can be separated into its component elements by chemical means. The ampere is the base unit for electric current in what metric system? - answerSI - The ampere is the base unit for electric current in the SI system. Mass depends on: - answerthe amount of material - Mass is an extensive property, which means it depends on how much of a substance there is. Which of the following units is a derived SI unit (not one of the SI base units)? - answernewton - Newtons are defined to be kg ms2. The other three units are base SI units. Which is the SI unit for length? - answermeters - Meters are the SI unit for length, and can be used to describe any length, large or small. Units of measurement provide which of the following? - answera standard comparison of measurements - It is only with agreed upon units of measure that measurements can be compared. For example, it is not possible to pick up a football field and place it next to another football field to ensure they have the same length, but with an an agreed upon definition of the length of a "yard" or a "foot" they can each be measured in yards or feet and the lengths compared. The magnitude of a measurement is determined by both the units and the numerical portion (120 yds is longer than 50 yds because 12050, and units do not convey any information about measurement uncertainty. Which of the following is NOT a base unit of SI? - answerounce - The second, the mole, and the meter are all SI units. Which prefix means one one-hundredth? - answercenti - Deci is one tenth, milli is one one-thousandth, and kilo is one thousand. Volume is the: - answerspace occupied by any sample of matter - Volume is the space occupied by any sample of matter. Which SI unit do we use to measure mass? - answerkilograms - We measure mass in kilograms. Volume is measured in liters, length is measured in meters, and time is measured in seconds. Which has a greater mass, 1 kg of rocks or 1 kg of feathers? - answerthey will be equivalent - 1 kg is a particular mass, it does not depend on the substance. Two objects that each have a mass of 1 kg will necessarily have the same mass regardless of their identity. In some cases, volume can be found by cubing which of the following quantities? - answerlength - Volume can be considered length times width times height, or a length in each of three spatial dimensions. In November 2018, the kilogram was redefined in terms of Planck's constant. Before this, the kilogram was based on: - answera cylinder of plat