Structure of Atoms
Anthing that has mass and takes up space.
Matter
Element's abbreviation; first letter is capitalized and second letter (if it has one) is lowercase.
chemical symbol
Symbols and subscripts used to represent a substance
chemical formula
Characteristic that helps to define or classify a substance
property
Process by which the atoms of an original substance rearrange to produce a new substance(s)
chemical reaction
Smallest complete part (building block) of matter.
Atom
Chemical property that describes the likelihood and rate at which a substance undergoes a chemical reaction.
Reactivity
Number at lower right of element's symbol in a formula; shows number of atoms for each element
subscript
Can be observed without changing the substance into a different substance
physical property
Reactions that cause heat
exothermic
Substance made of only one kind of atom.
element
Outermost electrons in the electron cloud; an element's valence electrons determine its chemical properties
Valence Electrons
Substance made of two or more atoms
molecule
Observed when a substance changes into a different substance
chemical change
Reactions that absorb heat
endothermic
Central part of an atom; contains most of its mass.
nucleus
What do you call the number of protons that an element has
atomic number
Molecule made of two or more elements
compound
In the human digestive system, chewing food into smaller pieces is a ________ change?
physical change
color change, temperature change, gas formation, or precipitate (solid) formation is often observed when a new substance(s) is formed during a chemical reaction
evidence of a chemical reaction
Part of an atom surrounding the nucleus; consists mostly of empty space in which electrons move.
electron cloud
Determines the identity of an element; this number also equals the number of electrons in a neautral atom
atomic number
Compound that includes carbon along with the element(s) hydrogen, oxygen, nitrogen, phosphorus, and/or sulfur
organic compound
Changing food's carbohydrates into simple sugars is a _____ change
chemical
New substances has different properties from the original substance
chemical reaction