topic 1 Flashcards
what are all substances made of?
atoms
what do atoms contain?
protons. neutrons & electrons
where is the nucleus?
in the middle of the atom
where are the neurons & protons contained?
in the nucleus
the nucleus has a _ charge because of the _?
positive, protons
where do the electrons move?
around the nucleus in electron shells
charge of electrons?
neg
number of _ EQUALS number of _
protons … electrons
in an ion, does the number of protons equal number of electrons? whats it mean?
no
means it has an overall charge
for example: ion w/ -2 charge has 2 more electrons that protons
the atomic number tells you ?
how many protons there are
the mass number tells you the total number of ?
protons and neutrons
how do you get the number of neutrons?
subtract atomic number from mass number
what is an element?
substance made up of atoms that all have the same number of protons in their nucleus.
definition of an isotope?
different form of the same element, which have the same number of protons but different number of neutrons.
EQ: relative atomic mass?
sum of (isotope abundance X isotopes mass number)
DIVIDED
sum of abundances of all the isotopes.
what is the relative atomic mass?
an average mass taking into account different masses and abundances
atoms join together to make _
compounds
when elements _ , atoms _ with others to make _
react, combine, compounds.
what are the compounds held together by?
chemical bonds
what does making bonds involve?
giving away, taking or sharing electrons.
how do you separate original elements of a compound out again?
a chemical reaction is needed.
the metal atoms _ electrons to form _ ions
lose, positive
non metal atoms _ electrons to form _ ions
gain, negative
what is ionic bonding?
opposite charges are attracted to each other.
a formula shows what?
what atoms are in a compound
formulas for:
- carbon dioxide
- water
- sodium chloride
- hydrochloric acid
- carbon monoxide
- CO2
- H2O
- NaCl
- HCL
- CaCl2
how do you separate insoluble solids from liquids?
filtration
how do you separate soluble solids from liquids?
evaporation &crystalisation
If an isotope has a mass number of 42 and an atomic number of 20, how many neutrons does it have?
22
How many electrons in Li+?
2
Electronic structure?
Electrons occupy shells around the outside of an atom. There can be up to two electrons in the first shell, up to eight in the second and up to eight in the third.
What happens to the ability to form an ion as you go down group 1?
increases
number of protons?
The number of protons in an atom is the same as the atomic number.
number of neutrons?
The number of neutrons is the mass number minus the atomic number
metals?
Metal atoms lose electrons when they react with non-metals. elements in Group 1 lose the electron from their highest occupied energy level (outer shell) to form ions with a +1 charge.
non-metals?
Non-metal atoms gain electrons when they react with metals. group 7 gain one electron into their highest occupied energy level (outer shell) to form ions with a –1 charge.
