Chemistry Flashcards
The study of matter.
Its chemical and physical properties and the chemical and physical changes it undergoes.
Chemistry
A specific substance that can’t be broken down into simpler substances by chemical reactions.
Element
Organized the elements into a periodic table.
Dmitri Mendeleev
Composed of atoms.
Matter
The smallest component/unit of an element that retails all of the chemical and physical properties of the element.
Contain a nucleus which contains protons and neutrons and is surrounded by electrons.
Atom
Central region of an atom.
Contains protons and neutrons.
Nucleus
Positively charged particles.
Located within the nucleus.
Protons
Particles with no electric charge.
Located within the nucleus.
Neutrons
Negatively charged particles.
Scattered around the outside of the nucleus in rings.
Electrons
Outer ring of electrons.
Important for chemical reactions.
Valence Electrons
# of protons + (average) # of neutrons
Atomic Mass
When an atom contains the same amount of protons and electrons, the positive and negative charges balance each other.
The atom is neutral.
Devised the original model of the atom, which depicted atoms like a solar system.
Niels Bohr
Atoms of the same element have the same number of protons and electrons but can have different numbers of neutrons.
Chemically identical, but may have different stabilities.
Isotopes
Result from the charges on 2 atoms interacting with each other (elements join and their atoms are held together).
3 main kinds: ionic bonds, covalent bonds, and hydrogen bonds.
Chemical Bonds