chemistry midterm

Which of the following is an example of a homogeneous mixture? a. air c. raw milk b. orange juice d. marble

a. air

In a glass tube attached to a voltage source, electrical current passes from the negative electrode, called the ____, to the other electrode. a. cathode c. electron b. anode d. millikan

a. cathode

According to the law of conservation of mass, when sodium, hydrogen, and oxygen react to form a compound, the mass of the compound is ____ the sum of the masses of the individual elements. a. equal to c. less than b. greater than d. either greater than or less than

a. equal to

In the equation density = mass/volume, mass divided by volume has a constant value. This means that the a. equation graphs as a straight line. b. variables mass and volume are inversely proportional. c. equation graphs as a hyperbola. d. product of mass and volume is a constant

a. equation graphs as a straight line

Which of these symbols represents a unit of volume? a. mL c. mm b. mg d. cm

a. mL

Standards of measurement are chosen because they a. can be related to everyday objects. b. are reproducible in another laboratory. c. cannot be destroyed by any common physical or chemical means. d. are easily changed.

b. are reproducible in another laboratory

Plasma is the fourth state of matter. In the plasma state a. atoms gain electrons. b. atoms lose electrons. c. atoms form molecules. d. atomic nuclei break down.

b. atoms lose electrons

Which of these is not an SI base unit? a. kilogram c. liter b. second d. Kelvin

c. liter

The total number of protons and neutrons in the nucleus of an atom is its a. atomic number. c. mass number. b. Avogadro number. d. average atomic mass.

c. mass number

The nucleus of an atom has all of the following characteristics except that it a. is positively charged. b. is very dense. c. contains nearly all of the atom's mass. d. contains nearly all of the atom's volume.

d. contains nearly all of the atom's volume

Experiments with cathode rays led to the discovery of the a. proton. c. neutron. b. nucleus. d. electron

d. electron

All of the following are SI units for density except a. kg/m3 . c. g/cm3 . b. kg/L. d. g/m2 .

d. g/m2 .

A physical change occurs when a a. peach spoils. b. silver bowl tarnishes. c. bracelet turns your wrist green. d. glue gun melts a glue stick.

d. glue gun melts a glue stick

Which of these is a measure of the amount of material? a. density c. volume b. weight d. mass

d. mass

Nitrogen monoxide and oxygen, both colorless gases, form a red-brown gas when mixed. Nitrogen monoxide and oxygen are called the a. products. c. synthetics. b. equilibria. d. reactants.

d. reactants.

Because any element used in the cathode produced electrons, scientists concluded that a. all atoms contained electrons. c. atoms were indivisible. b. only metals contained electrons. d. atoms carried a negative charge

a. all atoms contained electrons

Dalton incorporated the law of conservation of mass into his atomic theory by asserting that a. atoms are indivisible. b. atoms of different elements have different properties. c. matter is composed of atoms. d. atoms can be destroyed in chemical reactions.

a. atoms are indivisible

Because most particles fired at metal foil passed straight through, Rutherford concluded that a. atoms were mostly empty space. c. electrons formed the nucleus. b. atoms contained no charged particles. d. atoms were indivisible

a. atoms were mostly empty space

A state of matter in which a material has no definite shape but has a definite volume is the ____ state. a. gas c. plasma b. liquid d. solid

a. gas

If a mixture is uniform in composition, it is said to be a. homogeneous. c. heterogeneous. b. chemically bonded. d. a compound.

a. homogeneous

The most common form of hydrogen has a. no neutrons. c. two neutrons. b. one neutron. d. three neutrons.

a. no neutrons

A positively charged particle with mass 1.673 x 10-24 g is a(n) a. proton. c. electron. b. neutron. d. positron.

a. proton

Protons within a nucleus are attracted to each other by a. the nuclear force. c. their energy levels. b. opposite charges. d. electron repulsion

a. the nuclear force

An atom is a. the smallest unit of matter that maintains its chemical identity. b. the smallest unit of a compound. c. always made of carbon. d. smaller than an electron.

a. the smallest unit of matter that maintains its chemical identity

The liter is defined as a. 1000 m3 . c. 1000 g3 . b. 1000 cm3 . d. 1000 c3

b. 1000 cm3

A sample of gold has a mass of 96.5 g and a volume of 5.00 cm3 . The density of gold is a. 0.0518 g/cm3 . c. 101.5 g/cm3 . b. 19.3 g/cm3 . d. 483 g/cm3 .

b. 19.3 g/cm3

0.25 g is equivalent to a. 250 kg. c. 0.025 mg. b. 250 mg. d. 0.025 kg.

b. 250 mg

If 63.5 g of copper (Cu) combine with 16 g of oxygen (O) to form the compound CuO, how many grams of oxygen will be needed to combine with the same amount of copper to form the compound CuO2? a. 16 g c. 64 g b. 32 g d. 127 g

b. 32 g

What is the density of 37.72 g of material whose volume is 6.80 cm3 ? a. 0.180 g/cm3 c. 30.9 g/cm3 b. 5.55 g/cm3 d. 256. g/cm3

b. 5.55 g/cm3

How is the measurement 0.000 065 cm written in scientific notation? a. 65 x 10-6 cm c. 6.5 x 10-6 cm b. 6.5 x 10-5 cm d. 6.5 x 10-4 cm

b. 6.5 x 10-5 cm

If each atom of element D has 3 mass units and each atom of element E has 5 mass units, a molecule composed of one atom each of D and E has a. 2 mass units. c. 15 mass units. b. 8 mass units. d. 35 mass units

b. 8 mass units

. A compound is a. a pure substance that cannot be broken down into simpler, stable substances. b. a substance, made of two or more atoms that are chemically bonded, that can be broken down into simpler, stable substances. c. the smallest unit of matter that maintains its chemical identity. d. any substance, whether it is chemically bonded or not.

b. a substance, made of two or more atoms that are chemically bonded, that can be broken down into simpler, stable substances

The deflection of cathode rays in Thomson's experiments was evidence of the ____ nature of electrons. a. wave c. particle b. charged d. spinning

b. charged

Nuclear forces exists because the particles in the nucleus are a. oppositely charged. c. highly energized. b. close together. d. moving very fast.

b. close together

The density of an object is calculated by a. multiplying its mass times its volume. b. dividing its mass by its volume. c. dividing its volume by its mass. d. adding its mass to its volume.

b. dividing its mass by its volume.

Which part of an atom has a mass approximately equal to 1/2000 of the mass of a common hydrogen atom? a. nucleus c. proton b. electron d. neutron

b. electron

A theory is best described as a a. series of experimental observations. b. generalization that explains a body of known facts or phenomena. c. scientifically proven fact. d. testable statement

b. generalization that explains a body of known facts or phenomena

After measuring the ratio of the charge of a cathode-ray particle to its mass, Thomson concluded that the particles a. had no mass. c. had a very large mass. b. had a very small mass. d. carried a positive charge.

b. had a very small mass

. If a mixture is not uniform throughout, it is called a. homogeneous. c. chemically bonded. b. heterogeneous. d. a solution.

b. heterogeneous

As the atomic number increases, the number of electrons in a neutral atom a. decreases. c. remains the same. b. increases. d. is undetermined.

b. increases.

Matter includes all of the following except a. air. c. smoke. b. light. d. water vapor

b. light

Atoms of the same element can differ in a. chemical properties. c. atomic number. b. mass number. d. number of protons and electrons

b. mass number

Isotopes are atoms of the same element that have different a. principal chemical properties. c. numbers of protons. b. masses. d. numbers of electrons.

b. masses

A nuclear particle that has about the same mass as a proton, but with no electrical charge, is called a(n) a. nuclide. c. electron. b. neutron. d. isotope.

b. neutron.

The nucleus of deuterium contains one proton and a. two neutrons. c. no neutrons. b. one neutron. d. two electrons.

b. one neutron

In Rutherford's experiments, most of the particles a. bounced back. c. were absorbed by the foil. b. passed through the foil. d. combined with the foil.

b. passed through the foil

All known chemical elements are organized into groups based on similar chemical properties in the a. chemical chart. c. element table. b. periodic chart. d. None of the above

b. periodic chart

The two most important properties of all matter are a. the ability to carry an electric current well and to hold electric charge. b. taking up space and having mass. c. being brittle and hard. d. being malleable and ductile.

b. taking up space and having mass

When an electrical current passed through a glass tube, it caused the surface of the tube directly across from the cathode to glow. Scientists concluded that a. a magnetic field was produced. b. the particles of the beam were negatively charged. c. there was gas in the tube. d. atoms were indivisible.

b. the particles of the beam were negatively charged

Under ordinary conditions of temperature and pressure, the particles in a gas are a. closely packed. b. very far from one another. c. held in fixed positions. d. unevenly distributed.

b. very far from one another.

. How many minutes are in 1 week? a. 168 min c. 10 080 min b. 1440 min d. 100 800 min

c. 10 080 min

The measurement 0.020 L is the same as a. 2.0 x 10-3 L. c. 2.0 x 10-2 L. b. 2.0 x 102 L. d. 2.0 x 10-1 L.

c. 2.0 x 10-2 L.

If 6.0 g of element K combine with 17 g of element L, how many grams of element K combine with 85 g of element L? a. 17 g c. 30. g b. 23 g d. 91 g

c. 30. g

When 6.02 x 1023 is multiplied by 9.1 x 10-31, the product is a. 4.3 x 10-8 . c. 4.3 x 10-7 . b. 4.3 x 1054 . d. 4.3 x 10-5

c. 4.3 x 10-7

Which of these statements does not describe a measurement standard? a. Measurement standards avoid ambiguity. b. Measurement standards must be unchanging. c. A standard can be easily changed to suit the experiment. d. Confusion is eliminated when the correct measurement is applied.

c. A standard can be easily changed to suit the experiment

The relationship between the mass m of a material, its volume V, and its density D is a. D = mV. c. D = m/V. b. D = V/m. d. D = m + v.

c. D = m/V.

Which of these statements about density is true? a. Larger objects are more dense. b. Density does not depend on temperature. c. Density is a physical property. d. The density of an object depends on the force of gravity

c. Density is a physical property

What happens to the energy in a substance when it changes state? a. It is destroyed. b. It is changed into matter. c. It changes form, but is neither destroyed nor increased. d. The energy remains unchanged.

c. It changes form, but is neither destroyed nor increased.

Which of these statements about units of measurement is not true? a. A unit compares what is being measured with a previously defined quantity. b. A unit is usually preceded by a number. c. Measurements can be compared without knowing their units. d. The choice of unit depends on the quantity being measured.

c. Measurements can be compared without knowing their units

A mixture is a. a combination of pure substances bonded chemically. b. any substance with a uniform composition. c. a blend of any two or more kinds of matter, as long as each maintains its own unique properties. d. any group of elements that are chemically bonded to one another.

c. a blend of any two or more kinds of matter, as long as each maintains its own unique properties

A homogeneous mixture is also called a. chemically bonded. c. a solution. b. a compound. d. a solute.

c. a solution

A solid substance is a. always frozen regardless of its container. b. always a crystal regardless of its container. c. always the same shape regardless of its container. d. always losing particles regardless of its container.

c. always the same shape regardless of its container.

The metric unit for length that is closest to the diameter of a pencil is the a. micrometer. c. centimeter. b. millimeter. d. decimeter.

c. centimeter

All of the following are steps in the scientific method except a. observing and recording data. b. forming a hypothesis. c. discarding data inconsistent with the hypothesis. d. developing a model based on experimental results.

c. discarding data inconsistent with the hypothesis

Most of the volume of an atom is occupied by the a. nucleus. c. electrons. b. nuclides. d. protons.

c. electrons

. Which of these metric units is used to measure mass? a. m c. g b. mm d. L

c. g

Which of the following is an example of a heterogeneous mixture? a. a gold ring c. granite b. seawater d. sucrose

c. granite

Which of the following is not a chemical change? a. rusting c. melting b. igniting d. burning

c. melting

The most appropriate SI unit for measuring the length of an automobile is the a. millimeter. c. meter. b. kilometer. d. liter.

c. meter

A student recorded the following while completing an experiment. Color of substance: yellow, shiny powder Effect of magnet: yellow, shiny powder was attracted The student should classify the substance as a(n) a. element. c. mixture. b. compound. d. plasma.

c. mixture

If two or more compounds are composed of the same two elements, the ratio of the masses of one element that combine with a fixed mass of the other element is a simple whole number. This is a statement of the law of a. conservation of mass. c. multiple proportions. b. mass action. d. definite composition

c. multiple proportions

Two variables are inversely proportional if their ____ has a constant value. a. sum c. product b. difference d. quotient

c. product

Two variables are directly proportional if their ____ has a constant value. a. sum c. quotient b. difference d. product

c. quotient

An atom is electrically neutral because a. neutrons balance the protons and electrons. b. nuclear forces stabilize the charges. c. the numbers of protons and electrons are equal. d. the numbers of protons and neutrons are equal.

c. the numbers of protons and electrons are equal

When density is measured, a. a graduated cylinder is always used. b. the units are always kg/m3 . c. the temperature should be specified. d. the material must be a pure substance.

c. the temperature should be specified

Which of the following is an extensive property of matter? a. melting point c. volume b. boiling point d. density

c. volume

A change in the force of gravity on an object will affect its a. mass. c. weight. b. density. d. kinetic energy.

c. weight

0.05 cm is the same as a. 0.000 05 m. c. 0.05 m. b. 0.005 mm. d. 0.5 mm

d. 0.5 mm

100 milliliters is equivalent to a. 1 hectoliter. c. 1 centiliter. b. 1 microliter. d. 1 deciliter.

d. 1 deciliter.

The average distance between the Earth and the moon is 386 000 km. Expressed in scientific notation, this distance is written as a. 386 x 103 km. c. 3.9 x 105 km. b. 39 x 104 km. d. 3.86 x 105 km.

d. 3.86 x 105 km.

If 1 inch equals 2.54 cm, how many centimeters equal 1 yard? a. 0.0706 cm c. 30.5 cm b. 14.2 cm d. 91.4 cm

d. 91.4 cm

Which of these statements about mass is true? a. Mass is expressed in pounds or newtons. b. Mass is usually measured with a spring scale. c. The mass of an object depends on the force of gravity acting on it. d. The mass of an object is determined by comparing it to an object of known mass.

d. The mass of an object is determined by comparing it to an object of known mass

It is easy to determine whether a substance is a metal if the substance is a. easy to break down into its components. b. very hard. c. very brittle. d. a good electrical and heat conductor

d. a good electrical and heat conductor

The graphs of two variables that are inversely proportional to one another is a. a straight line. c. a parabola. b. an ellipse. d. a hyperbola

d. a hyperbola

The smallest unit of an element that can exist either alone or in combination with other such particles of the same or different elements is the a. electron. c. neutron. b. proton. d. atom.

d. atom

Which of the following is not a physical change? a. grinding c. boiling b. cutting d. burning

d. burning

In early experiments on electricity and matter, an electrical current was passed through a glass tube containing a. water. c. liquid oxygen. b. gas under high pressure. d. gas under low pressure.

d. gas under low pressure

The liquid state of matter can be described as a. having definite shape and definite volume. b. having neither a definite shape nor a definite volume. c. having lost electrons owing to energy content. d. having a definite volume but not a definite shape.

d. having a definite volume but not a definite shape

. A statement that can be tested experimentally is a a. variable. c. generalization. b. model. d. hypothesis.

d. hypothesis.

The standard base unit for mass is the a. gram. c. meter. b. cubic centimeter. d. kilogram.

d. kilogram.

The symbols for units of length in order from largest to smallest are a. m, cm, mm, km. c. km, mm, cm, m. b. mm, m, cm, km. d. km, m, cm, mm

d. km, m, cm, mm

A measure of the quantity of matter is a. density. c. volume. b. weight. d. mass.

d. mass

. A true statement about mass is that a. mass if often measured with a spring scale. b. mass is expressed in pounds. c. as the force of Earth's gravity on an object increases, the object's mass increases. d. mass is determined by comparing the mass of an object with a set of standard masses that are part of a balance.

d. mass is determined by comparing the mass of an object with a set of standard masses that are part of a balance.

The SI base units for length and time are a. centimeter and second. c. centimeter and hour. b. meter and hour. d. meter and second.

d. meter and second.

Which of these is the abbreviation for the SI base unit of time? a. hr c. sec b. h d. s

d. s

A plausible explanation of a body of observed natural phenomena is a scientific a. control. c. law. b. experiment. d. theory.

d. theory.

In Rutherford's experiments, alpha particles a. passed through a tube containing gas. c. collided with electrons. b. were used to bombard a cathode plate. d. were used to bombard thin metal foil.

d. were used to bombard thin metal foil.

Whose series of experiments identified the nucleus of the atom? a. Rutherford c. Chadwick b. Dalton d. Bohr

a. Rutherford

The density of pure diamond is 3.5 g/cm3 . What is the volume of a diamond with a mass of 0.25 g? a. 0.071 cm3 c. 3.75 cm3 b. 0.875 cm3 d. 14 cm3

a. 0.071 cm3

The speed of light is 300 000 km/s. In scientific notation, this speed is written to one significant figure as a. 3 x 105 km/s. c. 3. x 106 km/s. b. 3.0 x 105 km/s. d. 3.0 x 106 km/s

a. 3 x 105 km/s