Q&A Hero

Q: Consider a neutral atom with 30 protons and 34 neutrons. The atomic number of the element is A) 30. B) 32. C) 34. D) 64. E) 94.

Q: What is the mass number of an atom of potassium that has 20 neutrons? A) 15 B) 19 C) 35 D) 39 E) 59

Q: The mass number of an atom can be calculated from A) the number of electrons. B) the number of protons plus neutrons. C) the number of protons. D) the number of electrons plus protons. E) the number of neutrons.

Q: The number of neutrons in an atom is equal to A) the atomic number. B) the mass number. C) the mass number + the atomic number. D) the mass number - the atomic number. E) the number of protons.

Q: The atomic number of an atom is equal to the number of A) nuclei. B) neutrons. C) neutrons plus protons. D) electrons plus protons. E) protons.

Q: In an atom, the nucleus contains A) an equal number of protons and electrons. B) all the protons and neutrons. C) all the protons and electrons. D) only neutrons. E) only protons.

Q: Which of the following descriptions of a subatomic particle is correct? A) A proton has a positive charge and a mass of approximately 1 amu. B) An electron has a negative charge and a mass of approximately 1 amu. C) A neutron has no charge and its mass is negligible. D) A proton has a positive charge and a negligible mass. E) A neutron has a positive charge and a mass of approximately 1 amu.

Q: According to the Atomic Theory, A) all atoms are different. B) atoms are neither created nor destroyed during a chemical reaction. C) atoms of the same element combine to form compounds. D) all matter is made up of tiny particles called electrons. E) a compound can contain different numbers of atoms as long as it has the same kinds of atoms.

Q: The smallest particle of an element that retains the characteristics of the element is a(n) A) electron. B) neutron. C) proton. D) atom. E) nucleus.

Q: The element in this list with chemical properties similar to magnesium is A) sodium. B) boron. C) carbon. D) strontium. E) chlorine.

Q: Semiconductors are located in the periodic table on (or in) the A) left side of the table. B) right side of the table. C) line dividing metals from nonmetals in the table. D) first period of the table. E) last period of the table.

Q: Identify the metalloid in the following list. A) sulfur B) fluorine C) silver D) copper E) germanium

Q: Identify the noble gas in the following list. A) helium B) nitrogen C) oxygen D) gold E) chlorine

Q: What is the symbol of the element in Period 4 and Group 2? A) Be B) Mg C) Ca D) C E) Si

Q: What is the symbol of the element in Group 4A(14) and Period 2? A) Be B) Mg C) Ca D) C E) Si

Q: Which element would have physical and chemical properties similar to chlorine? A) Ar B) Br C) S D) O E) P

Q: Which of the following elements is a noble gas? A) oxygen B) chlorine C) bromine D) argon E) nitrogen

Q: Which of the following elements is a nonmetal? A) nitrogen B) sodium C) iron D) silver E) calcium

Q: Which of the following is a characteristic of nonmetals? A) shiny B) malleable C) good conductors of heat D) low melting points E) good conductors of electricity

Q: Which of the following elements is a metal? A) nitrogen B) fluorine C) argon D) strontium E) phosphorus

Q: The Group 8A(18) elements A) are unreactive and are rarely found in combination with other elements. B) are good conductors of electricity. C) melt at high temperatures. D) are liquids at room temperature. E) react vigorously with water.

Q: Which of the following properties is NOT a characteristic of the Group 1A(1) elements (alkali metals)? A) They are shiny. B) They are good conductors of heat. C) They react vigorously with water. D) Most of them are liquids at room temperature. E) They are good conductors of electricity.

Q: Which of the following is a characteristic of the modern periodic table? A) A group is a horizontal row on the periodic table. B) A period is a column on the periodic table. C) The elements in each group have similar chemical properties. D) The B groups contain the representative elements. E) The A groups contain the transition elements.

Q: What elements are in hydroxyapatite, Ca5 (PO4)3OH, a major compound in human bones and teeth? A) carbon, potassium, oxygen, hydrogen B) calcium, phosphorus, oxygen, hydrogen C) carbon, phosphorus, oxygen, helium D) calcium, phosphorus, oxygen, helium E) carbon, potassium, oxygen, helium

Q: Select the correct symbol for the element. Ca is the symbol for A) calcium. B) carbon. C) cobalt. D) copper. E) cadmium.

Q: Select the correct symbol for the element. silver A) S B) Si C) Ag D) Au E) AG

Q: Select the correct symbol for the element. potassium A) P B) Po C) Pt D) K E) Ko

Q: Select the correct symbol for the element. sodium A) So B) Na C) No D) Sm E) Au

Q: Select the correct symbol for the element. iron A) Ir B) Fs C) Fe D) In E) FE

Q: Select the correct symbol for the element. aluminum A) Al B) Am C) Au D) Sn E) Ag

Q: Au is the symbol for A) gold. B) silver. C) argon. D) aluminum. E) sodium.

Q: Identify each of the following transformations as a chemical or physical change A) physical B) chemical 1> water evaporating 2> a button falling off of a shirt 3> silver tarnishing 4> cutting the grass 5> a nail rusting 6> baking a cake 7> placing photographs in a scrapbook 8> formation of green leaves on a plant 9> burning leaves 10> melting ice

Q: Match the state of matter with each of the following descriptions of a substance. A) liquid B) solid C) liquid + gas D) gas E) solid + liquid 1>Particles are held close together in a random pattern. 2> Great distances exist between the particles. 3> This substance is boiling. 4> This material has a definite volume, and a definite shape. 5> This substance is melting.

Q: Identify the physical state(s) corresponding to the regions on the cooling curve below. A) liquid and gas B) liquid and solid C) solid and gas D) gas E) solid F) liquid 1> A 2> B 3> C 4> D 5> E

Q: The temperature at which water melts and freezes is the same.

Q: As a solid melts, its temperature does not change.

Q: When a liquid is boiling, its temperature does not change.

Q: As heat is removed from a solid, its temperature decreases.

Q: Condensation occurs when a liquid is converted to a solid.

Q: The units of specific heat are cal g/F.

Q: Carbohydrates and proteins have the same caloric value per gram.

Q: The energy in chemical bonds is kinetic energy.

Q: 32 F is the same temperature as 100 C.

Q: Water freezes at 100 C.

Q: Water vapor is a gas.

Q: Molecules of a gas are very close together.

Q: A solid has a constant shape and volume.

Q: Black coffee is a homogeneous mixture.

Q: Gold is an element.

Q: Bromine ) has a freezing point of -7 C, and a boiling point of 60 C. Indicate the state or change of state occurring at each temperature. 1> 30 C 2> 60 C 3> -7 C 4> -15 C 5> 70 C

Q: When a liquid boils, the process by which the molecules leave its surface is called ________.

Q: The change of state from solid to gas is termed ________.

Q: The units of specific heat are ________.

Q: Will the caloric value of a 100.g hamburger be higher or lower than the caloric value of 100. g of cooking oil?

Q: Will the caloric value of a 100. g hamburger be higher or lower than the caloric value of 100. g of sugar?

Q: The nutritional calorie (Cal) is the same as ________ cal.

Q: The energy of motion is called ________ energy.

Q: The boiling point of water on the Celsius scale is ________ C.

Q: The lowest temperature on the Kelvin scale is ________ kelvin.

Q: A reaction of a substance with water is an example of a ________ property.

Q: A color of a substance is an example of a ________ property.

Q: A mixture which has uniform properties is a ________ mixture.

Q: The simplest type of pure substance is an ________.

Q: Which of the following does NOT represent a step on the heating curve of water? A) The temperature of steam cannot exceed 100 C. B) The temperature of ice remains at 0 C as it melts. C) The temperature of liquid water increases linearly as it is heated. D) The temperature of liquid water remains at 100 C as it boils. E) Both liquid water and ice are present at 0 C.

Q: A heating curve illustrates A) what a substance looks like as it is heated. B) what happens to the particles of a substance as it is heated. C) what happens to the heat applied as the temperature is increased. D) the changes in the temperature and physical state of a substance as it is heated. E) the chemical changes that occur as the substance is heated.

Q: Which of the following does NOT involve a change of state? A) melting ice B) freezing water C) vaporization of alcohol D) sublimation of dry ice E) pouring water into a vacuum-insulated bottle

Q: When a solid is converted directly to a gas, the change of state is called A) freezing. B) melting. C) boiling. D) condensation. E) sublimation.

Q: The formation of a gas resulting from the escape of high-energy particles from the surface of a liquid is known as A) evaporation. B) deposition. C) boiling. D) melting. E) sublimation.

Q: The physical state(s) present when a substance is melting is (are) A) solid. B) liquid. C) gas. D) solid + liquid. E) liquid + gas.

Q: A burn from steam at 100 C is expected to be more severe than a burn from boiling water at 100 C because A) the steam is hotter than the boiling water. B) there is more steam than water. C) the steam will give off a large amount of heat as it condenses. D) you are more likely to come into contact with the steam than with the boiling water. E) All of these answers are correct.

Q: The specific heat of copper is 0.0920 cal/g C, and the specific heat of silver is 0.0562 cal/g C. If 100 cal of heat is added to one g of each metal at 25 C, what is the expected result? A) The copper will reach a higher temperature. B) The silver will reach a higher temperature. C) The two samples will reach the same temperature. D) The copper will reach a temperature lower than 25 C. E) The silver will soften.

Q: The number of calories needed to raise the temperature of 32 g of water from 12 C to 54 C is A) 384 cal. B) 1.3 cal. C) 1300 cal. D) 1700 cal. E) 0.76 cal.

Q: Raising the temperature of 10.0 g of water from 10.0 C to 20.0 C requires 100.0 cal of energy, while raising the temperature of 10.0 g of aluminum from 10.0 C to 20.0 C requires 22 cal. More calories are required to heat the water because A) water is a liquid and aluminum is a solid at 10.0 C. B) ten grams of water occupies a larger volume than 10.0 g of aluminum. C) water has a greater potential energy than aluminum. D) water has a larger specific heat than aluminum. E) 10.0 C is closer to the melting point of water than to the melting point of aluminum.

Q: How many calories are required to raise the temperature of a 150. g sample of gold from 25 C to 175 C? The specific heat of gold is 0.0308 cal/g C. A) 4.62 cal B) 116 cal C) 22500 cal D) 693 cal E) 130 cal

Q: How many calories are required to increase the temperature of 13 g of alcohol from 11 C to 23 C? The specific heat of alcohol is 0.588 cal/g C. A) 83 cal B) 0.63 cal C) 92 cal D) 0.54 cal E) 170 cal

Q: How many calories are required to raise the temperature of a 35.0 g sample of iron from 25 C to 35 C? Iron has a specific heat of 0.108 cal/g C. A) 38 cal B) 1.1 cal C) 3.8 cal D) 93 cal E) 130 cal

Q: A kilocalorie of heat is required to raise the temperature of A) 1 g of water from 14 C to 15 C. B) 1 g of water by 10 C. C) 10 g of water by 10 C. D) 100 g of water by 10 C. E) 100 g of water by 100 C.

Q: The specific heat of a substance is the amount of heat needed to A) change 1 g of the substance from the solid to the liquid state. B) raise the temperature of 1 g of the substance by 1 C. C) change 1 g of the substance from the liquid to the solid state. D) convert 1 g of a liquid to gas. E) convert 1 g of a solid to a gas.

Q: One cup of kidney beans contains 15 g of protein, 1.0 g of fat, and 42 g of carbohydrate. How many kilocalories, to two significant figures, does this sample contain? A) 60 kcal B) 88 kcal C) 230 kcal D) 240 kcal E) 520 kcal

Q: A diet has a total caloric intake of 1400 kcal. If the protein in the diet provides 35% of the kcal, the number of kcal of protein in the diet is A) 700 kcal. B) 490 kcal. C) 210 kcal. D) 460 kcal. E) 1200 kcal.