2) Atoms, ions + compounds Flashcards
nitrate ion
NO3 -
carbonate ion
CO3 2-
sulfate ion
SO4 2-
hydroxide ion
OH -
ammonium ion
NH4 +
zinc ion
Zn 2+
silver ion
Ag +
The atom consists of a _ made up of 2 types of subatomic particles: _ and _. Also, _ occupy a region outside the nucleus and are arranged in _.
nucleus protons neutrons electrons shells
What is the overall charge of an atom?
zero
What is the symbol, charge and relative mass of a proton?
p+
1+
1
What is the symbol, charge and relative mass of a neutron?
n
0
1
What is the symbol, charge and relative mass of an electron?
e-
1-
1/1836
Define atomic (proton) number
the number of protons in the nucleus of an atom
What does the number of protons identify?
the element
Define isotope
atoms of the same element with different numbers of neutrons and different masses
Define mass number
the sum of the number of protons and neutrons in the nucleus; nucleon number
In heavy water, what isotope do all H2O molecules contain?
deuterium isotope
Define ion
a positively (cation) or negatively (anion) charged atom or a (covalently bonded) group of atoms (polyatomic ion), where the number of electrons is different from the number of protons
The mass of a carbon-12 isotope is defined as_?
exactly 12 atomic mass units
What is the standard mass for atomic mass?
1 u, 1/12th of an atom of carbon-12
What is 1u approximately?
the mass of a proton or neutron
Define relative isotopic mass
mass of an atom of the isotope compared with 1/12 of the mass of an atom of carbon-12
Define relative atomic mass, Ar
weighted mean mass of all isotopes of the element (in a sample) compared with 1/12 of the mass of an atom of carbon-12
What can be used to determine the percentage abundances of isotopes in a sample of an element?
mass spectrometer
Give the 3 steps for using a mass spectrometer
- sample placed in the mass spectrometer, vaporised and ionised to form positive ions
- ions are accelerated. heavier ions move more slowly and are more difficult to deflect than lighter ions, so the ions of each isotope are separated
- ions are detected on a mass spectrum as a mass-to-charge ratio m/z. each ion reaching the detector adds to the signal, so the greater the abundance, the larger the signal
mass-to-charge ratio = ?
relative mass of ion / relative charge on ion
For an ion with a one positive charge, this ratio is equivalent to _?
the relative isotopic mass (x-axis)
relative atomic mass = ?
((RIM x abundance) + …) / total abundance
Define binary compound
a compound containing to elements only
Define polyatomic ion
an ion containing more than one atom
Normally metals _ e- to form _ and non-metals _ e- to form _.
lose
cations
gain
anions
Give 7 examples of diatomic molecules
H2 N2 O2 F2 Cl2 Br2 I2
Give 2 examples of polyatomic molecules
P4
S8
State symbol for a gas?
(g)
State symbol for a liquid?
(l)
State symbol for a solid?
(s)
State symbol for dissolved in water / aqueous?
(aq)
