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One question set, multiple game modes. Tap any game to see it in action. Not sure which to pick?
Answer to place stones and capture territory.
Outrun the snow together.
Earn blasts, then hunt the other team.
Answer to earn energy, then climb.
The class blasts through walls together.
Bid on mystery lots. Most money wins.
Sell tours. Nice, standard, or a total scam.
Answer, restock, and serve the rush.
More correct answers pulls the rope your way.
Answer, then shoot down the alien wave.
Answer, then tap to leap the frozen ridge.
Vinegar is added to baking soda in a cup, and bubbling begins immediately. Which observation is evidence that a chemical reaction occurred?
Two clear solutions are poured together, and a bright yellow solid appears in the liquid. Which observation is the reaction evidence?
A strip of magnesium is placed in acid. The thermometer reading changes from 22°C to 34°C while the mixture reacts. Which observation shows reaction evidence?
Steel wool is heated in air and changes from gray to reddish-brown. Which observation supports that a chemical reaction happened?
Calcium chloride solution is mixed with sodium carbonate solution, and the mixture turns cloudy white. Which observation is the best evidence of reaction?
Which observation gives the strongest evidence that a new substance formed?
A student records four lab observations. Which one is evidence of a chemical reaction rather than only a physical change?
Which lab note does NOT by itself show evidence of a chemical reaction?
Which observation is the weakest evidence that a chemical reaction occurred?
Two colorless solutions are mixed. The temperature rises by 8°C and a white solid appears. What is the best conclusion?
A zinc strip is placed in blue copper sulfate solution. The blue color fades, a reddish coating forms on the strip, and the beaker warms. What is the best conclusion?
A dry white powder is heated in a test tube. A gas inflates a small balloon, and the remaining solid is yellow after cooling. What conclusion fits the observations?
A student mixes two clear salt solutions and wants evidence that a new product formed. Which additional observation would best support that claim?
A student heats a dry white powder and wants more evidence it changed chemically. Which added observation would best support the claim?
A metal strip is placed in a colorless solution. Which extra observation would best support that a chemical reaction occurred?
A cold pack gets colder as ammonium nitrate dissolves in water. How is the dissolving process classified?
A hand warmer becomes hot after iron powder reacts with oxygen inside the packet. What classification fits the reaction?
When HCl(aq) and NaOH(aq) are mixed in a foam cup, the solution temperature rises from 21 °C to 34 °C. What happened?
A mixture of baking soda and citric acid in a sealed bag feels cold while it reacts. For the reacting chemicals, which label is correct?
Calcium chloride dissolves in water and the cup becomes warm. What is the best classification for dissolving CaCl2?
Photosynthesis stores energy from sunlight while forming glucose from CO2 and H2O. How is the overall process classified?
A propane grill heats the air and food as C3H8 burns. What classification applies to the combustion reaction?
A beaker gets very cold during the reaction of barium hydroxide with ammonium thiocyanate. What does that observation show about the reaction?
Cellular respiration of glucose releases usable energy and heat. How should the overall reaction be classified?
A thermometer in a reacting mixture drops from 25 °C to 17 °C while the reaction continues. For the reaction system, what classification fits?
A reaction has ΔH = -82 kJ. What does the negative sign show?
For dissolving KNO3 in water, ΔH = +34.9 kJ/mol. What does the plus sign mean?
A thermochemical equation gives ΔH = -394 kJ for forming 1 mol of CO2. Which heat-flow statement is correct?
Calorimetry gives ΔHrxn = +18 kJ. Which interpretation fits this result?
Glucose combustion is listed with ΔH = -2803 kJ per mole of glucose. Which classification matches this sign?
A reaction step has ΔH > 0. Which statement must be true for that step?
If ΔH is negative for A → B, which statement about the reaction is correct?
A chemical process is measured with ΔH = +6.0 kJ. What classification and heat flow match the sign?
Methane combustion releases heat. Which equation places heat on the correct side?
Decomposing calcium carbonate requires heating: CaCO3 forms CaO and CO2. Which placement is correct?
Liquid water freezes and releases heat. Which thermochemical equation shows the heat placement correctly?
An ice cube melts by absorbing energy from its surroundings. Which equation places heat correctly?
A neutralization warms the solution: HCl(aq) + NaOH(aq) forms NaCl(aq) and H2O(l). Which equation fits?
For N2(g) + O2(g) → 2NO(g), ΔH = +180.5 kJ. How should heat be shown?
Electrolysis of water requires energy to form hydrogen and oxygen gases. Which equation best represents the energy placement?
Water vapor forms frost directly on a freezer wall and gives off heat. Which equation places heat correctly?
In a reaction, the products have more stored chemical energy than the reactants. What is true about the overall energy change?
The products of a reaction have lower enthalpy than the reactants. Which conclusion follows?
An energy diagram lists reactants at 80 kJ and products at 140 kJ. What is ΔH for the reaction?
Reactants are at 200 kJ on an energy diagram, and products are at 75 kJ. Which result is correct?
After bonds rearrange, the products are 30 kJ higher in enthalpy than the starting substances. What must have happened?
On an energy profile, the product level is 25 kJ below the reactant level. Which statement matches the profile?
A reaction stores energy in its products, leaving them higher in enthalpy than the reactants. Which heat-flow statement is correct?
Which energy comparison matches an exothermic reaction?
Water evaporates from skin and the skin feels cooler. For the water, how is evaporation classified?
Steam condenses into liquid droplets on a cool lid. For the water vapor system, what happens to heat?
Dry ice changes directly from CO2(s) to CO2(g). How is this phase change classified?
Liquid wax solidifies as a candle cools. For the wax, which energy direction is correct?
Frost forms when water vapor changes directly to ice on a cold window. How is the phase change classified for the water?
An ice cream mixture freezes in a freezer. For the mixture, what is the heat-flow direction?
Crack the passcode before the zombies get in.
Answer, then swat bugs for bonus points.
Race through questions at your own speed.
Same question on every screen. Fastest wins.
Pick a tile, answer, hit bonuses and steals.
