Chapter 9 & 10 Science Vocab

atom

atom

the smallesst piece of an element that still represents that element

electron

a particle with one negative charge

nucleus

a small area in the center of an atom where most if an atom’s mass and positive charge is concentrated

proton

an atomic particle that has one positive charge

neutron

a neutral particle that exissts in the nucleus of an atom

electron cloud

an area around an atomic nucleus where an electron is most likely to be located

ion

an atoms that is no longer neutral befcause it has gained or lost electrons

atomic number

the number of protions in an atom of an element

isotope

atoms of the same element that have different numbers of neutrons

mass number

the sum of the number of protons and neutrons in an atom

average atomic mass

the average mass of the element’s isotopes, weighted according to the abundance of each isotope

radioactive

elements that spontaneously emit radiation

nuclear decay

a process that occurs when an unstable atomic nucleus changes into another more stable nucleus by emitting radiation

periodic table

a chart of the elements arranged into rows and columns according to their physical and chemical properties

group

a column on the periodic table

period

the rows on the periodic table

metal

an element that is generally shiny, easily pulled int othin sheets, and a good conductor of electricity and thermal energy

luster

describes the ability of a metal to reflect light

ductility

the ability to be pulled into thin wires

malleability

the ability of a substance to be hammered or rolled into sheets

alkali metal

the elements in group 1

alkaline earth metal

the elements in group 2 on the periodic table

transition element

the elements in group 3-12

nonmetal

elements that have no metalic properties

halogen

an element in group 17 of the periodic table

noble gas

th element in group 18 of the periodic table

metalloid

an element that has physical and chemical properties of both metals and non metals

semiconductor

conducts electricity at high temperatures but not low temperatures