Question | Answer |
Mendeleev | organized the first periodic table |
atomic mass | the average mass of one atom of the element |
periodic table | a table of elements arranged in a regular, repeating pattern |
nucleus | the core of the atom |
proton | a subatomic particle with a + charge |
neutron | a subatomic particle with no charge |
electron | a subatomic particle with a - charge |
atomic mass unit (amu) | the mass of a proton or neutron |
atomic number | the number of protons in an atom's nucleus |
chemical symbol | a shortened form for an element |
group | the elements in a column on the periodic table |
family | another name for group |
period | a row on the periodic table |
valence electrons | electrons located in the outer most shell
that are involved in forming chemical bonds |
malleable | material that can be pounded into shapes |
ductile | material that can be pulled out, or drawn, into a long wire |
conductor | materials that can transmit heat and electricity |
reactivity | the ease or speed that an element combines or reacts with other elements or compounds |
corrosion | the process in which metal react with oxygen to form metal oxides |
alloy | a mixture of metals |
diatomic molecules | nonmetals that form molecules of two identical atoms |
semiconductors | substances that can carry electricity under some conditions, and under other conditions, cannot |
plasma | a state of matter in which atoms are stripped of their electrons and the nuclei are packed closely together |
nuclear fusion | atomic nuclei combine to form a larger nucleus, releasing huge amounts of energy |
supernova | a tremendous explosion that breaks apart a massive star producing high temperatures |