chapter 5.2 Flashcards
periodic law
when elements are arranged by an increasing number of protons, properties repeat in a pattern
what are columns called?
groups
what is similar about the elements in the same group?
similar chemical properties; same number of valence electrons
what are the rows called?
period
how many periods are there?
7
what is the last elements in most periods?
noble gases
what is the first element in a period?
very reactive metals
what does the element key tell us?
atomic number, chemical symbol, element name, average atomic mass
what is the most common state of metals?
solids, excepts for mercury
ductility
able to be drawn into thin wires
malleability
able to be hammered without shattering
conductivity
allowing heat or energy to pass through
transition metals
bridge between elements on the right and left side of the table
are nonmetals similar to metals?
no, their properties are generally opposite of metals
are non-metals good conductors?
no they cannot carry heat or electricity well
what is the boiling point of nonmetals?
very low
what is the most common state of nonmetals?
gases at rm temp
nonmetal malleability:
nonmetals are brittle, no malleability
do metalloids have conductivity?
ability to carry heat and electricity varies with temperature
where are metalloids on periodic table?
the stair-step pattern
when moving to the right of a table, what happens to the atomic size, metallic properties, and ability to lose an electron?
it decreases
when moving to the right of a table, what happens to the ability to gain electrons?
it increases, except for noble gases
where do we get atomic mass?
the distribution of an element’s isotopes in nature and masses
how is atomic mass defined?
1/12 the mass of a carbon-12 atom
weighted average
where some values are more important than other values
how many elements occur naturally?
92 elements
metals in groups 3-12 are called?
transition metals
valence electron?
electron that is in the highest occupied energy level of an atom
the number of an A group matches…
the number of valence electrons in electron configuration
