ATOMS • • ________________-‐ the basic unit of matter. Contains subatomic particles o _____________________ (+ charge) o _____________________ (no charge/neutral) o _____________________ (-‐ charge) • • ELEMENTS AND ISOTOPES • • ___________________-‐ a pure substance that consists of only one type of atom. Elements are represented by a 1 or 2 letter symbol. (ie: C = carbon) The number of ___________________ in an element is that element’s _______________________.
o The atomic number of carbon is 6, therefore carbon has 6 protons and consequently 6 neutrons. • ISOTOPES • _________________-‐ atoms of the same element that have different numbers of neutrons. o Isotopes are identified by their _________________________________________________ (ie: carbon-‐12, carbon-‐13, carbon-‐14) • • The _____________________________________________ of the masses of an element’s isotopes is called its _____________________________.
Isotopes have the same number of _______________________, so all isotopes of an element have the same ______________________________________. Mass Number-‐ the sum of the number of ________________________ plus the number of ________________________. Protons and neutrons have about the same mass. Electrons are much ________________. Atoms have equal numbers of __________________________ and ___________________________. o Because these particles are opposite charges, the whole atom is _______________.
RADIOACTIVE ISOTOPES • Some isotopes are _____________________________. This means that their nuclei are unstable and break down at a continuous rate over time. IONS • _______________-‐ an atom that has gained or lost an electron, giving it a positive or negative charge. o ___________________-‐ a positively charged ion o ___________________-‐ a negatively charged ion CHEMICAL COMPOUNDS • _______________________-‐ formed by the chemical combination of two or more elements in definite proportions. o Compounds are typically written as a __________________________________________ (ie: NaCl, CO2, etc.) This gives you the ratio elements in the compound. o The physical and chemical properties of a compound are usually very different from those of the elements form which it is formed. • • CHEMICAL BONDS • ___________________________________-‐ formed when one or more electrons are transferred from one atom to another.
o Form between a _____________________ and a