4200 Question Chemical Reactions A student applies heat to a solid substance. Which indicates that a chemical change occurred?The substance becomes a liquid but solidifies when cooled.The substance changes color and stays that color when cooled.C. The substance goes from liquid to gas very quickly.D. The substance expands but stay s the same color.
5200 Answer Chemical Reactions B. The substance changes color and stays that color when cooled.??
6300 Question Chemical Reactions Which of these represent chemical change?A. A match lit, creating a yellow-orange flameB. A small piece of ice melts, changing from a solid to a liquidC. A ball of clay sinks in the water, and floats when reshaped.D. A pot of water is heated to boiling, and evaporation occurs.
7300 Answer Chemical Reactions A. A match lit, creating a yellow-orange flame??
8400 Question Chemical Reactions A chemical equation is shown below:The element zinc (Zn) can best be described as aCompoundMixtureGasreactant
9400 Answer Chemical Reactions Reactant(Starting material in a chemical reaction)??
10500 Question Chemical Reactions Which sample equation best illustrates the law of conservation of mass?12 grams reactant X + 10 grams reactant Y ---- 2 grams product Z5 grams reactant E + 5 grams reactant F --- 20 grams product G + 5 grams product H4 grams reactant U + 3 grams reactant V --- 7 grams product W10 grams reactant Q + 9 grams reactant R --- 90 grams product S + 90 grams product T
11500 Answer Chemical Reactions C. 4 grams reactant U + 3 grams reactant V --- 7 grams product W??
12100 QuestionLife ScienceThe Arctic environment has temperatures that range between -22° C and 6° C with snow covering some of the area. Which adaptation would most likely help a population of organisms survive this environment?Long necks and tall legsLarge shell and leathery skinLight colored fur and layers of blubberBrightly colored feathers and webbed feet
13100 Answer Life ScienceC. Light colored fur and layers of blubber??
14200 QuestionA student observes a tree with small needle-like leaves that stay green year round. Which conclusion can the student draw from the shape of the leaves?The leaves of the tree do not perform photosynthesis.The leaves of the tree have an illness that stunts their growth.The leaves of the tree are nonfunctional.The leaves of the tree are intended to reduce water loss.
15200 Answer Life SciencesD. The leaves of the tree are intended to reduce water loss.??
16Which organisms are most likely to be the same approximate age? 300 Question Life ScienceCompare the fossil layersWhich organisms are most likely to be the same approximate age?1 and 33 and 52 and 45 and 6
18400 Question Life ScienceTwo fossils that appear to be from the same type of organism are found in two different layers of rock. The layers of rock are shown here.Which can be determined from the location of the fossils?The prey of the organismsThe predators of the organismThe cause of death for each organismThe relative age of each organism
19400 Answer Life ScienceD. the relative ageof each organism??
20500 Question Life Science To what class does the organism belong? Cestoda B. GastropodaC. Trematoda D. Bivalvia
22100 Question Forces of Nature What keeps earth in its orbit?The rotation of earthThe gravity of the sunThe revolution of the moonThe gravity of the moon100 Question Forces of Nature
23100 Answer Forces of Nature B. The gravityof the sun??
24200 Question Forces of Nature A nuclear power plant has recently been built to generate electricity for a town located near several small lakes. Which is not a benefit of this nuclear power plant being built?The cost of the electricity will decrease.The loss of habitat for local wildlife.The heating of homes will be easier.The nuclear power plant will supply jobs.
25200 Answer Forces of Nature B. The loss of habitat for local wildlife.??
26300 Question Forces of Nature A student coils a copper wire around a bar magnet. Which action will cause the device to generate electricity?A. The student connects the copper wire to a light bulb.B. The student insulates the copper wire with plastic.C. The student uses a horseshoe magnet instead of a bar magnet.D. The student moves the bar magnet through the copper wire coils.
27300 Answer Forces of Nature D. The student moves the bar magnet through the copper wire coils.??
28400 Question Forces of Nature Wire coils spinning between two magnets will producecoldelectricitysteamchemicals
32100 Question Solids, Liquids , Gases Oh My! The graph below represents the percentages of gases that make up the atmosphere of Earth.Which gas is represented in the portion labeled 1 on the graph?ArgonHydrogenNitrogenOxygen
33100 Answer Solids, Liquids , Gases Oh My! C. Nitrogen??
34200 Question Solids, Liquids , Gases Oh My! Which diagram best shows the type of particle arrangement associated with a gas?
36300 Question Solids, Liquids , Gases Oh My! A student performed a classroom investigation by mixing a purple liquid and a white powder. Diagrams of the setup and the resulting blue solid are shown.The student could best classify this reaction as aPhysical change B. Weight changeC. mass change D. Chemical change
37300 Answer Solids, Liquids , Gases Oh My! D. Chemical change??
38400 Question Solids, Liquids , Gases Oh My! A student designs an experiment to test the acidity of the water in several ponds near an industrial area. Which tool would best help a student obtain accurate data?Oxygen probeMetric rulerpH indicatorHeat sensor
40500 Question Solids, Liquids , Gases Oh My! Which properties most likely indicate that a substance is a base?Releases hydrogen gas and reacts with metalsTurns red litmus blue and conducts an electric currentTurns blue litmus red and conducts an electric currentHas a pH below seven and corrodes a nail
41500 Answer Solids, Liquids , Gases Oh My! B. Turns red litmus blue and conducts an electric current??(Bases feel slippery, change litmus blue, and become less basic when mixed with acids)
42100 Question odds and endsThe main biofuel on the market today is ethanol, a fuel made from corn. Which type of bioengineered product is ethanol?AdaptiveAssistiveResistantManipulated
44200 Question odds and endsWhich statement best describes what the planet Saturn, a lizard, and a steaming kettle have in common?All are made of atoms.All are multicellular organisms.All are at the same internal temperature.All produce their own energy without help.
45200 Answer odds and endsAll are made of atoms???
46300 Question Odds and EndsA student observes that a gas is formed when chemical Y is added to chemical Z in the lab. The student’s observation of a new product being formed is the common outcome of allPhysical changesChemical changesMass changesPhase changes
50500 Question Odds and EndsA 5-gram sample of water occupies 5 milliliters of space in a beaker.Using the formula, what is the density of the water sample?1 gram/milliliter5 grams/milliliter10 grams/milliliter25 grams/milliliter