Atomic Structure and the Periodic Table Flashcards
What is atomic number?
the number of protons in the nucleus of an atom
What is mass number?
the total number of protons and neutrons in the nucleus of an atom
How can we find out how many electrons are in the outer shell of an atom?
seeing what group it is
eg. group 7- 7 electrons in outer shell
How do we know how many electron shells are in an atom?
seeing what period it is
eg. period 3 - 3 shells
Define ‘isotopes’.
different atoms of the same element that have the same number of protons but different numbers of neutrons
Do isotopes of the same element have the same chemical properties? Why?
yes, because they have the same number of electrons and same electronic configuration
What is the melting point trend in Group 1 alkali metals?
melting point decreases as you go down
What is the density trend in Group 1 alkali metals?
density increases as you go down
What is the reactivity trend in Group 1 alkali metals?
reactivity increases as you go down
What is formed when an alkali metal reacts with water?
metal hydroxide and hydrogen gas
State properties of metals.
malleable, ductile, high density conduct heat and electricity, generally high melting points
State properties of non-metals.
do not conduct, brittle, low density, low melting point
How do the group VII halogens exist naturally?
diatomic
What happens to the density of halogens as you go down the group?
density increases
as you go down
What happens to the reactivity of halogens as you go down the group?
reactivity decreases
as you go down
