Chemical Change
Give one example of a physical property.
flexibility, color, hardness, shine, texture
What are reactants?
The substances at the beginning of a chemical reaction
What is one piece of evidence that a chemical reaction has occurred?
Formation of a new substance
a group of same atoms
What are molecules?
Atomic behavior is largely determined by the number of what in an atom?
What are valence electrons?
Anything that has mass and takes up space is called...
Matter
What are products?
The new substances formed in a chemical reaction
Classify this chemical reaction: CaCO3 = CaO + CO2
Decomposition
a substance that is made from molecules fo more than one element
What is a compound?
The number of chemically joined atoms necessary to form a molecule
What is two or more?
What is an endothermic reaction?
a reaction in which energy is absorbed
What does the principle of conservation of matter state?
During a chemical reaction, matter cannot be created or destroyed.
If I perform a chemical reaction inside of a glass container, have I performed a closed or open system reaction? Why?
Closed- the matter cannot escape.
compounds form in these ways
What are many different ways?
Name a molecule pair.
What is hydrogen?
What is an exothermic reaction?
A reaction that releases energy, mostly in the form of heat.
What is a closed system chemical reaction?
What is a closed system chemical reaction?
bases that can be dissolved in water are called these
What is alkalis?
most of the things you see in everyday life are not pure elements or compounds, they are these
What are mixtures?
Term used for "sharing electrons."
What is covalent bonding?
this occurs whenever there is a change in a substance's molecules
What is a chemical change?
this causes molecules to break apart
What is energy?
solid, liquid, and gas
What are the 3 states of matter?
scientists use formulas in these to show changes
What are equations?
What are synthetic substances?
a substance or compound formed under human control by a chemical reaction. Synthetic substances to improve their quality of life of humans.