Physical vs. Chemical
What kind of change takes place when metal rusts? Explain.
Chemical Reaction/Change. Rust is a different substance, different color, and cannot be turned back into regular metal.
What is the smallest unit of a chemical element—everything that exists is made up of these.
An Atom
A solid
The temperature changes on its own.
any of more than 100 substances that cannot by ordinary chemical means be separated into different substances
An Elementary Substance
What kind of change takes place when water boils and you can see bubbles as the water is heated? Explain.
Physical Change. Water changes into a different form of matter but remains as H2O.
A mixture of two or more substances that appears to be a single, uniform medium, with no visible separation between its components
Homogeneous Mixture
What form of matter has a fixed volume, but no fixed shape?
What is a sign that a chemical reaction has occurred, which relates to the color of a substance?
The color changes
a mixture of two or more substances that remain as physically separate substances
A Heterogeneous Mixture
What kind of change takes place when batter is baked and becomes a cake? Explain.
Chemical Reaction/Change. Cake changes has different properties and cannot be turned back into batter.
What is the term for two or more atoms bonded together?
A molecule
What form of matter has no fixed volume and no fixed shape?
A gas
A chemical reaction leads to the formation of a ___ ________
What is the term for two or more types of atoms bonded together?
A compound
What kind of change takes place when warm water and sugar are added to yeast, causing bubbles to form?
Chemical. The formation of bubbles signifies a chemical change.
a chemical change that occurs when two or more substances combine to form a new substance
Chemical Reaction
What term refers to a fluid with a viscosity that changes depending on the force exerted on it?
Non-Newtonian fluid
Fill in the blank: Chemical reactions are _______ because the reaction cannot be undone easily or naturally.
irreversible
Mixtures
What kind of change takes place when dry ice turns directly into a gas while exposed to warm temperatures? Explain.
Physical Change. Carbon Dioxide (Dry Ice) changes in its state of matter (solid-->gas), but is still Carbon Dioxide. No new substance is formed.
The big number in a chemical equation, that tells us how many of a type of molecule is present.
Coefficient
What is the term that refers to a solid turning directly into a gas? (like with dry ice)
Sublimation
True or False? Bubbles forming in a substance is a sign that a chemical reaction has occurred?
True
What is the term for a solid that forms from a liquid solution during a chemical reaction, and the solid doesn't dissolve?
A precipitate