click below
click below
Normal Size Small Size show me how
chemist chapter 3
chemastry chapter 3
Question | Answer |
---|---|
atom | a basic unit of matter that consists of a dense, central nucleus surrounded by a cloud of negatively charged electrons. |
plum-pudding model | the atom is composed of electrons surrounded by a soup of positive charge to balance the electrons' negative charges, like negatively-charged "plums" surrounded by positively-charged "pudding". |
gold-foil experiment | he shot a very thin peice of gold foil with a stream of postively charged particles known as the alpha particles. he found that most of the alpha particles passed sraight through the foil. |
orbitals | the aria of space an electron takes up |
nucleus | consists of protons and neutrons |
proton | positavly charged electron |
neutron | negetavly charged electron |
mass number | the total number of protons and neutrons |
atomic number | is the number of protons found in the nucleus of an atom |
ion | an atom or molecule that has gained or lost one or more electrons |
isotopes | are different types of atoms of the same chemical element, each having a different number of neutrons |
atomic mass | is the mass of a specific isotope of a given atom, most often expressed in unified atomic mass units |
valence electrons | determns how the atom reacts chemically with other atoms. |
octet | Group of eight valence electrons surrounding an atom. |
excited state | state in which an atom or molecule picks up outside energy |
ionization energy | the minimal energy required to remove an electron from the atom |
electron affinity | the energy change when an electron is added to the neutral species |