Definitions
Lets Practice
Reactant & Products
Exothermic & Endothermic
100
The new substance that forms during a chemical reaction.
Product
100
A scientist counts 24 atoms in the reactants before a chemical reaction occurs. After the reaction, how many atoms should be found in the products?
24 atoms
100
In a chemical reaction, a reactant is...
The old substance that exists before the chemical reaction
100
Releases more energy into the surroundings than it absorbs.
Exothermic Reaction
200
A solid substance that is formed when two liquids are combined during a chemical reaction.
Precipitate
200
During Chemical Reactions the properties of substances will ...
change into different properties.
200
In a chemical reaction, a product is...
The new substance that exists after the chemical reaction.
200
Absorbs more heat than they release.
Endothermic Reaction
300
A shorthand notation made up of chemical formulas that summarize a chemical reaction.
Chemical Equation
300
Think about what happens during a chemical reaction. Which statement best describes what is happening at the atomic level?
The atoms in the substances break apart and reconnect in the same way they were before.
The bonds between atoms in the reactants break and reform to make new products.
The bonds between atoms grow until a substance changes states.
The atoms that form extended structures rearrange themselves and disappear.
The bonds between atoms in the reactants break and reform to make new products.
300
Identify the reactants of this chemical equation
300
The prefix "exo" means
out or outside
400
The Scientific Law which states that matter is not created nor destroyed; that the mass and atoms of the reactants must equal that of the products.
Conservation of Matter
400
When you mix a little lemon juice with baking soda in a cup, bubbles appear, the mixture may feel a little cooler, a soft white solid forms, and the color of the mixture changes slightly. Which of the following can be observed as evidence of a chemical reaction?(Gas, Color Change, Precipitate, Energy Transfer).
Gas, Color Change, Precipitate, Energy Transfer
400
Does this table follow the Law of Conservation of Matter?
No, the number of reactants do not equal the number of products
400
The prefix "endo" means
in or inside
500
When one or more new substances form from one or more other substances.
Chemical Reaction
500
Name the four clues that you can observe during a chemical reaction.
Gas, Precipitate, Color Change, and Energy Transfer
500
Does the mass of the chemical equation follow the Law of Conservation of Matter?
Yes, the mass of the reactants equals the mass of the products at 8.6 grams.
500
What type of reaction is this:
You use an instant cold pack after a sports injury. When you squeeze the pack, chemicals inside mix together and the pack begins to feel cold. The reaction absorbs heat from your skin to occur, which is why the area feels cooler.
Endothermic Reaction