Chemical Reactions
This observable sign of a chemical reaction occurs when two clear liquid solutions are mixed and form an insoluble solid.
Precipitate
To balance a chemical equation properly, you may only change these numbers placed before formulas, never the subscripts.
Coefficients
Crushing a solid reactant into a fine powder increases this factor, allowing more collisions to occur at once.
Surface area
This term describes the body's ability to maintain a stable internal environment despite external changes.
homeostasis
This primary mechanism of evolution occurs when organisms with traits better suited to their environment survive and reproduce more successfully.
natural selection
In this specific type of chemical reaction, a single complex compound breaks down into two or more simpler substances.
Decomposition Reaction
These are the starting substances listed on the left side of a chemical equation's yield arrow.
Reactants
Increasing this measurement causes reactant particles to move faster and collide with higher kinetic energy.
Temperature
Sweating to cool down when hot is an example of this primary feedback loop that counteracts a change to restore balance.
negative feedback
Inherited structural or behavioral traits that improve an organism's chance of surviving in its environment are called these.
adaptations
During a reaction in a closed container, the total mass before and after remains identical due to this fundamental law.
Law of Conservation of Mass
This coefficient belongs in front of $H_2O$ to balance the equation 2H2 + O2 → ________ H2O.
2
Refrigerating food prevents it from spoiling quickly because cold conditions decrease this specific property of chemical reactions.
Reaction rate
Unlike negative feedback, this type of loop amplifies a stimulus or change until a specific end result is achieved, such as during childbirth contractions.
positive feedback
When a physical barrier like a river or storm separates a population into distinct groups, preventing them from interbreeding, this type of isolation occurs.
Isolation
When an acid reacts with a carbonate material, such as stone or baking soda, it produces water, a salt, and this specific gas.
Carbon dioxide (CO2)
This coefficient belongs in front of H2 when balancing the synthesis of ammonia: N2 + ____H2 → 2NH3.
3
This scientific theory states that chemical reactions only occur when particles crash into each other with correct orientation and sufficient energy.
Collision Theory
When blood glucose levels rise after a meal, the pancreas releases this hormone to help cells take in glucose and lower blood sugar.
insulin
The similar anatomical bone arrangement found in human arms, bat wings, and whale flippers provides evidence of common ancestry known as this.
comparative morphology
A chemical reaction that absorbs thermal energy from its surroundings, causing the temperature to drop, is classified as this.
Endothermic Reaction
To balance the equation for rust formation, 4Fe + ___O2 → 2Fe2O3, this coefficient is needed in front of oxygen gas.
3
These biological catalysts speed up chemical reactions in living organisms by lowering the required activation energy.
Enzymes
When blood glucose drops between meals, the liver releases stored sugar into the blood due to the action of this hormone.
glucagon
Any environmental factor—such as smooth rocks, predators, or food supply—that determines which individuals survive better and reproduce is called this
selection pressure