domek first semester exam

Determine the correct METRIC length of the grasshopper in this image.

2.5 centimeters

Medical x-rays have wavelengths between 0.1 nm and 0.01 nm. Which of the following could be the frequency of a medical x-ray? A. 8 x 1018 Hz B. 8 GHz C. 8 x 10 -18Hz D. 8 Hz

A

80. The highest energy level of sodium contains _________ electron(s). A. 1 B. 2 C. 4 D. 8

A. 1

Which represents an atom of calcium?A. 1 B. 2 C. 3 D. 4

A. 1

Kristen has 7.5 mL of water and her lab partner, Rebecca, has 2.3 L of water. How many total microliters do they have? A. 23 075 000 mL C. 230 750 mL B. 23 075 mL D. 2 307 500 mL

A. 2307500

The symbols for a metal, a non-metal and a noble gas IN THAT ORDER are A. Ba, P, Ar B. Ag, Ga, Xe C. Ce, Ge, Ne D. Ca, Sn, Kr

A. Ba, P, Ar

What is the first step that should be taken when a caustic chemical gets into a person's eyes? A. Flush the affected area with water. C. Call for an ambulance. B. Identify the chemical D. Apply a neutralizing agent.

A. Flush the affected area with water

Which of the groups below has the electron dot structure shown above A. Halogens B. Noble Gases C. Alkali metals D. Alkaline earth metals

A. Halogens

While experimenting with cathode-ray tubes, _______ discovered the electron.A. J. J. Thomson B. Ernest Rutherford C. Niels Bohr D. John Dalton

A. JJ thomson

Which element listed below would be expected to have properties similar to lithium? A. K B. Mg C. Sc D. Si

A. K, Potassium

In comparison with liquids and gases, solids generally are A. More dense C. more compressible B. Less organized D. more likely to flow to fill their containers

A. More dense

Which best describes the relationship between subatomic particles in any neutral atom?A. The number of protons equals the number of electrons. B. The number of protons equals the number of neutrons C. Then number of neutrons equals the number of electrons. D. The number of neutrons is greater than the number of protons.

A. The number of protons equals the number of electrons

Which of the following observations is qualitative? A. The substance is a shiny solid at room temperature. B. There are a dozen beakers of liquid on the counter. C. The substance has a mass of 124.3 g. D. The volume of water in the graduated cylinder was 34.5 mL.

A. The substance is a shiny solid at room temperature

Elements in a group of the periodic table are described below. Some Properties of a Certain Group of Elements • Soft silvery-white color • Good conductor of thermal energy • Good conductor of electricity • Atoms contain a single valence electron These elements most likely belong to which group? A. Alkali metals B. Alkaline earth metals C. Halogens D. Noble gases

A. alkali metals

69. For the most common types of radioactive decay, the order of least dangerous to most dangerous is A. alpha, beta, gamma B. beta, gamma, alpha C. gamma, beta, alpha D. gamma, alpha, beta

A. alpha, beta, gamma

Which of the following properties do solids share with liquids? A. definite volume C. fluidity B. definite shape D. do not diffuse

A. definite volume

A sample of sulfur obtained from the crater of a volcano is carefully measured. Which of the following is an intensive property of the sample? A. Density of 2.07 g/cm3 B. Mass of 3.85 g C. Volume of 1.86 cm3 D. Length of 5.65 cm

A. density

The student determines that the unknown substance is sodium chloride. Which of the following is an extensive property of sodium chloride? A. Mass of 15 g B. White color C. Density of 2.17 g/cm3 D. Solubility in water

A. mass of 15g

Which set of terms correctly describes a slice of an apple? A. matter, heterogeneous, mixture C. heterogeneous, solution, matter B. compound, homogeneous, solid D. mixture, solid, homogeneous

A. matter, heterogenous, mixture

In general the periodic table of elements contains more A. metals than nonmetals B. metalloids than nonmetals C. nonmetals than metals D. metalloids than metals

A. metals than notmetals

Which color of the visible spectrum would represent the greatest emission of energy? A. red B. violet C. blue D. yellow

A. red

Which total mass is the smallest?A. the mass of 2 electrons. B. the mass of 2 neutrons C. the mass of 1 electron plus the mass of 1 proton D. the mass of 1 neutron plus the mass of 1 electron

A. the mass of two electrons

. As a distant star moves away from Earth, the light given off by the star has a measurably lower frequency. What happens to the wavelength and energy of the photons of light when the frequency becomes lower? A. The wavelength becomes longer and the energy decreases. B. The wavelength becomes shorter and the energy decreases. C. The wavelength becomes longer, and the energy increases. D. The wavelength becomes shorter, and the energy increases.

A. the wavelength becomes longer and he energy decreases

Round the number 0.54 499 999 to two significant figures. A. 0.5 B. 0.54 C. 0.55 D. 0.1

B 0.54

The concept of the atom has been around since the days of the ancient, but over the years our knowledge of atomic structure has changed significantly. Which model is known as the Bohr model?A. B. C.

B.

The element chlorine exists as two naturally occurring isotopes. Cl-35 occurs 75% of the time and Cl-37 occurs 25% of the time. Which of the following calculations should be used to calculate the correct average atomic mass of chlorine A. (35 amu x 3) + 37 amu 2 B . (35 amu x .75) + (37 amu x .25) C. (35 amu x 3) + 37 amu 3 D. 35 amu + 37 amu

B. (35amu x .75) + (37amu x .25)

A scientist has found the following isotope of oxygen:A. 8 B. 11 C. 19 D. 27

B. 11

Which of these would be the best instrument to measure 15.5 mL of water? A. 25 mL beaker C. 25 mL Erlenmeyer flask B. 25 mL graduated cylinder D. 25 mL test tube

B. 25 ml graduated cylinder

Place the following models about the structure of the atom in the order that they were developed:A. 1, 3, 2 B. 3, 1, 2 C. 2, 3, 1 D. 1, 2, 3

B. 3,1,2

What is the hammer's density, using the correct number of significant figures?A. 0.300 g/mL B. 3.33 g/mL C. 3.61 g/mL D. 7.55 g/mL

B. 3.33 g/mL

What is the volume of the water in the graduated cylinder above? A. 4.41 mL B. 4.39 mL C. 4.55 mL D. 5.61 mL

B. 4.39 mL

Carson and his lab partner conducted flame tests of several metallic salt solutions. They dipped a wire loop into each salt solution, and one by one, heated the sample in the Bunsen burner flame. What caused the different colored flames produced by each salt solution? A. Excited electrons emit specific quanta of energy when heated in the flame. B. Excited electrons fall back to ground state releasing a discrete amount of energy represented by a flame color. C. Excited electrons are released into the flame and their energy causes the flame to change color. D. Excited metal atoms are released from chemical bonds and the excess energy is released, illustrated by a specific color.

B. Excited electrons fall back to ground state releasing a discreete amount of energy represented by a flame color

If you catch on fire, you should A. Panic and be sure to run as quickly as possible to blow out the flames. B. Head for the nearest safety shower OR use fire blanket OR stop/drop/roll. C. Pull the fire alarm and look for help, hoping the fire doesn't burn you too badly. D. Continue with the experiment because you need a good grade.

B. Head for the nearest safety shower OR use fire blanket OR stop/drop/roll

How should you smell a chemical? A. Stick your nose close to the container and breathe deeply. B. Hold the container away from you and gently fan the vapors toward you. C. You should NEVER smell a chemical under any circumstances. D. Smell the chemical just as you would anything else.

B. Hold the container away from you and gently fan the vapors towards you.

A zero (0) in the blue square of the National Fire Protection Association diamond hazard sign indicates A. the chemical is very flammable. B. the chemical is not dangerous to your health. C. the chemical is very dangerous to your health. D. the chemical is very reactive.

B. The chemical is not dangerous to your health

A student investigated the physical and chemical properties of a sample of an unknown gas and then identified the gas. Which statement represents a conclusion rather than an experimental observation? A. The gas is colorless. B. The gas is carbon dioxide. C. When the gas is bubbled into limewater, the liquid becomes cloudy. D. When placed in the gas, a flaming splint stops burning.

B. The gas is carbon dioxide

A student sets up an experiment to investigate the effect of temperature on the volume of 50 grams of gas inside a balloon. Which statement correctly describes the design of the experiment? A. The mass of the gas is a control and the temperature is the independent variable. B. The volume is a control and the temperature is the dependent variable. C. The temperature is a control and the mass of the gas is the dependent variable. D. The temperature is a control and the volume is the independent variable.

B. The volume is a control and the temperature is the dependent variable

Eating and drinking are not permitted in the lab because A. there will not be enough time to finish the experiment. B. you could be poisoned. C. you will leave crumbs. D. there is no microwave to heat your food.

B. You could be poisoned

Bronze contains 90-95% copper and 5-10% tin. Because these percentages can vary, bronze is classified as A. a compound C. an element B. a mixture D. a pure substance

B. a mixture

A student determined in the laboratory that the percent by mass of water in copper sulfate pentahydrate is 40.0%. If the accepted value is 36%, what is the percent error? A. 0.11% B. 1.1 % C. 11 % D. 10.0 %

B. bohrs

For an electron in an atom to change from the ground-state to an excited state, A. energy must be released B. energy must be absorbed C. visible light must be seen D. the electron must change from a higher energy level to a lower energy level.

B. energy must be absorbed

The element in Group 17 Period 4 is A. a transition metal C. an alkali metal B. a halogen D. a noble gas

B. halogen

The symbols for units of length in order from largest to smallest are A. mm, cm, m, km C. mm, m, cm, km B. km, m, cm, nm D. km, mm, cm, m E. nm, cm, m, km

B. km, m cm, nm

Isotopes of an element have differentA. atomic numbers C. numbers of protons B. mass numbers D. numbers of electrons

B. mass numbers

Which process represents a chemical change? A. cutting wire B. oxidation of iron C. evaporation of water D. boiling water

B. oxidation of iron

Which of the following is NOT a form of electromagnetic radiation? A. X-rays B. sound waves C. visible light D. gamma rays

B. sound waves

Dry ice is used in some fire extinguishers. The dry ice is stored in the cylinder in a solid form. When sprayed on a fire, it quickly changes into the gas form without going through the liquid state. This change of state is called A. Vaporization C. condensation B. Sublimation D. deposition

B. sublimation

The value 8.004 x 10-3 in standard (ordinary) notation would be: A. 8004 B. 800.4 C. 0.0084 D. 0.00084

C

An element that is malleable and a good conductor of heat and electricity could have an atomic number of A. 16 B. 18 C. 29 D. 35

C. 29

David measured the mass of his pencil on an electronic scale. How many significant figures are there in his recorded measurement of 5.430 grams? A. 1 B. 2 C. 3 D. 4

C. 3

The picture above shows a small section of elements from the periodic table. Which element has one less proton than element X? A. 1 B. 2 C. 3 D. 4

C. 3

This Bohr model of aluminum (shown below) has _____ energy levels with _____ valence electrons A. 1, 2 B. 2, 3 C. 3, 3 D. 4, 8

C. 3,3

47. A thin sheet of aluminum measures 0.094 cm x 33.2 cm x 15.00 cm. The volume of aluminum rounded off to the correct number of significant figures is A. 46.81 cm3 B. 46.812cm3 C. 47 cm3 D. 50 cm3

C. 47 cm^3

What is the total number of subatomic particles (protons + electrons + neutrons) in an atom of Vanadium-51? (Vanadium's symbol is V).A. 46 B. 51 C. 74 D. 125

C. 74

Which of these conclusions can be drawn from Rutherford's experiment (above)?A. Each atom contains electrons. C. Atoms are mostly empty space. B. The nucleus of an atom can be split. D. Each atom contains protons.

C. Atoms are mostly empty space

Which pair of atoms contain the same number of neutrons?A. Lithium-7 and beryllium-9 B. Potassium-40 and potassium-41 C. Calcium-42 and argon-40 D. Nitrogen-14 and oxygen-16

C. Calcium-42 and argon-40

Which of these represents a release of energy (exothermic)? A. H2O (s) à H2O (l) C. H2O (g) à H2O (l) B. H2O (l) à H2O (g) D. H2O (s) à H2O (g)

C. Hz0 gas to H20 liquid

The _________________ variable in an experiment could be informally called the 'cause' while the __________________ could be called the 'effect'. A. Control; dependent B. Control; independent C. Independent; dependent D. Dependent; independent

C. Independent, dependent

According to the data below, and knowing that the expected amount of solution is 15.5 mL, what conclusion can you draw regarding Method A and Method B? A. Method A is accurate only and Method B is both precise and accurate. B. Method A is both accurate and precise, and Method B is accurate but not precise. C. Method A is accurate only and Method B is precise but not accurate. D. Method A is precise only and Method B is accurate only.

C. Method A is only accurate and method B is precise but not accurate

Which of the following includes an example of a chemical property of an element? A. Aluminum is a solid at room temperature and is a poor thermal insulator. B. Sulfur is not shiny and is not malleable. C. Sodium is a solid at room temperature and reacts with other elements. D. Silicon is shiny and is a poor conductor of electricity.

C. Sodium is a solid at room temperature and reacts with other elements

Thorium-234 is produced in an alpha decay reaction as shown in the following reaction. __________________ 4 He + 234 Th 2 90 What radioactive element decays to produce Th-234? A. Pu - 236 B. Ra-230 C. U -238 D. Ta- 240

C. U-238

Which phrase describes an atom?A. a positively charged electron cloud surrounding a positively charged nucleus. B. a positively charged electron cloud surrounding a negatively charged nucleus. C. a negatively charged electron cloud surrounding a positively charged nucleus. D. a negatively charged electron cloud surrounding a negatively charged nucleus.

C. a negatively charged electron cloud surrounding a positively charged nucleus

Which group identifies chemical properties? A. malleability, ductility, conductivity B. density, melting point, boiling point C. combustibility, flammability, reactivity D. luster, hardness, texture

C. combustibility, flammability, reactivity

What group of matter cannot be broken into smaller parts through normal chemical or physical means? A. elements C. compounds B. homogeneous mixtures D. heterogeneous mixtures

C. compounds

Which of the properties of bromine is/are chemical properties? A. 1 and 3 only B. 2 and 4 only C. 4 only D. 4, 5, and 6 only

C. four only

In which of the following three states of matter are the particles moving the fastest? A. Solid C. gas B. Liquid D. they all move the same

C. gas

Which of the following states of matter assume the volume and shape of their container? A. Solids C. gases B. Liquids D. all of the above

C. gas

Which of these measurements has 3 significant figures? A. I and II only B. II and III only C. I and III only D. I, II, and III

C. one and three only

Find the frequency of an electromagnetic wave with 2.35 x 10-22 J energy. A. 3.00 x 10-12Hz B. 4.87 x 109Hz C. 1.55 x 109Hz D. 3.55 x 1011Hz

D

What is the proper scientific notation for 12 500 000? A. 12.5 x 106 B. 1.25 x 10-7 C. 1.25 x 106 D. 1.25 x 107

D. 1.25 x 10^7

What element is produced by the beta decay in the following nuclear reaction? A. 33 Si C. 34 Si 14 14 B. 34P D. 34S 16 16

D. 34 S 16

Which of the following is a mixture? A. Carbon B. Glucose (C6H12O6) C. Distilled water D. Air

D. Air

Octane, a component of gasoline, can be represented by the chemical formula C8H18. What type of substance is octane? A. homogeneous mixture C. element B. heterogeneous mixture D. compound

D. Compound

Who is credited with developing the first Periodic Table? A. Moseley B. Newlands C. Rutherford D. Mendeleev

D. Mendeleev

Which of the following periods on the periodic table contains the greatest number of metals? A. Period 1 B. Period 2 C. Period 3 D. Period 4

D. Period 4

Cyndy places 3 beakers in the freezer. The first beaker contains water only, the second contains water and salt, and the third contains a water and sugar solution. Cyndy recorded temperature and the time at which each mixture froze. What is the most appropriate hypothesis for her experiment? A. Salt affects the freezing point of water. B. The addition of salt raises the freezing point of water. C. The addition of a sugar lowers the freezing point of water. D. The addition of different substances affects the freezing point of water.

D. The addition of different substances affects the freezing point of water

A student designed this experiment to study the effects of a catalyst (something that speeds up a reaction). Which trial serves as the experimental control? A. Trial 1 B. Trial 2 C. Trial 3 D. Trial 4

D. Trial 4

In the modern periodic table, elements are ordered A. according to Mendeleev's original design. B. according to decreasing atomic number. C. based on when they were discovered. D. according to increasing atomic number.

D. according to increasing atomic number

Which set of verbs below indicates ALL chemical changes? A. corrode, grind, melt, rust B. freeze, rot, explode, condense C. boil ferment, crumple, burn D. tarnish, corrode, oxidize, rust

D. luter, hardness, texture

Which of the following is NOT a way that matter changes phase? A. melting C. vaporization B. freezing D. mixing

D. mixing

Which of the following correctly lists electromagnetic waves in order from longest to shortest wavelength? A. gamma rays, ultraviolet, infrared, microwaves B. microwaves, ultraviolet, visible light, gamma rays C. radio waves, infrared, gamma rays, ultraviolet D. television, infrared, visible light, X-rays

D. television, infrared, visible light, X-rays