2.1.1 Atomic structure and isotopes Flashcards
definition for relative isotopic mass
the mass of an atom of a single isotope relative to the 1/12th of a carbon 12 atom
definition of relative atomic mass
the weighted mean mass of an atom of an element relative to the 1/12th of a carbon 12 atom, talking into account isotopic abundance
equation for RAM
(iso 1 x abun) + (iso 2 x abun)
—————————————-
100
hydroxide ion formula
OH-
nítrate ion formula
NO3-
sulphate ion formula
SO4^2-
carbonate ion formula
CO3^2-
method for writing ionic equations
separate the aqueous compounds into its ions
balance equation fully
remove spectator ions
rewrite equation without the spectator ions
how many electrons can the first electron shell hold
2 electrons
how many electrons can the second electron shell hold
8 electrons
how many electrons can the third electron shell hold
18 electrons
how many electrons can the fourth electron shell hold
32 electrons
definition of an orbital
regions of space around the nucleus that can hold two electrons with opposite spin
what shape is an s orbital
sphere shape
what shape is a p orbital
a dumbell shape (figure of 8)
how many orbitals are in the sub level s
1
how many orbitals are in the sub level p
3
how many orbitals are in the sub level d
5
what are the maximum number of electrons in sub level s
2
what are the maximum number of electrons in sub level p
6
what are the maximum number of electrons in sub level d
10
what is the order for electron configuration
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6
what is the Pauli exclusion principle
each orbital can hold TWO electrons with opposite spins
what is Hund’s rule
within a sublevel place on electron per orbital before pairing them
(use this during box arrow electron configuration)
what elements do not have the expected electron structure
Chromium and Copper
what is the electron structure of chromium
1s2 2s2 2p6 3s2 3p6 4s1 3d5
what is the electron structure of copper
1s2 2s2 2p6 3s2 3p6 4s1 3d10
how are gallium , kryptons and transition metals ion electron configuration different
they lose the 4s electrons first then the 3d electrons
acid + metal
salt + hydrogen
acid + metal oxide
salt + water
acid + metal hydroxide
salt + water
acid + metal carbonate
salt + water + carbon dioxide
What are the three sub-atomic particles?
Proton, Neutron, Electron
Protons and neutrons are located in the nucleus, while electrons are found in orbitals.
Where is the proton located in an atom?
Nucleus
Where is the neutron located in an atom?
Nucleus
Where is the electron located in an atom?
Orbitals
What is the relative mass of an electron?
1/1800
What is the atomic number (Z)?
The number of protons in the nucleus.
What is the mass number (A)?
The total number of protons and neutrons in the atom.
How do you calculate the number of neutrons in an atom?
A - Z
What are isotopes?
Atoms of the same element with the same number of protons but different numbers of neutrons.
Do isotopes have similar chemical properties?
Yes, because they have the same electronic structure.
What is relative isotopic mass?
The mass of one isotope compared to one twelfth of the mass of one atom of carbon-12.
What is relative atomic mass?
The average mass of one atom compared to one twelfth of the mass of one atom of carbon-12.
What is relative molecular mass?
The average mass of a molecule compared to one twelfth of the mass of one atom of carbon-12.
How is the relative atomic mass (R.A.M) calculated?
R.A.M = E (isotopic mass x % abundance) / 100
What is the R.A.M of magnesium (Mg) if the isotopic masses and abundances are: 78.7% Mg24, 10.13% Mg25, and 11.17% Mg26?
24.3
Fill in the blank: Relative atomic mass of an element is a ______ of all the isotopes.
weighted average
Calculate the R.A.M of Tellurium given the following abundances: 124-Te (2), 126-Te (4), 128-Te (7), 130-Te (6). What is the result?
127.8
What are the two isotopes of copper?
63-Cu and 65-Cu
What is the relative atomic mass of copper?
63.5
True or False: The mass spectra for Cl and Br shows that Cl has two isotopes C/35 (75%) and C|37(25%).
True
What is the relative abundance of Br79 and Br81?
50% each
In mass spectra, what does the peak at 160 represent?
Double the abundance of the other two peaks.
What is the Bohr model of the atom?
An early model predicting electrons in spherical orbits with 2 electrons in the first shell and 8 in the second shell.
What are the principal energy levels in an atom?
Numbered 1, 2, 3, 4, with 1 being closest to the nucleus.
What are the sub-energy levels in an atom?
Labelled s, p, d, and f.
How many electrons can each sub-level hold?
- s holds up to 2 electrons
- p holds up to 6 electrons
- d holds up to 10 electrons
- f holds up to 14 electrons
What is the order of filling sub-shells in an atom?
1s→2s→2p→3s→3p→4s→3d→4p→5s→4d→5p.
What do orbitals represent?
Mathematical probabilities of finding an electron at any point within certain spatial distributions around the nucleus.
What are the shapes of s and p orbitals?
- s sublevels are spherical
- p sublevels are shaped like dumbbells.
How is electronic structure represented for oxygen?
1s² 2s² 2p⁴.
How do spin diagrams represent electrons?
An arrow represents one electron, and arrows going in opposite directions represent different spins in the orbital.
What does a s block element indicate?
It is one whose outer electron is filling an s-sub shell.
What is the rule for filling orbitals with several sub-levels?
Fill each orbital singly before starting to pair up the electrons.
What happens when a positive ion is formed?
Electrons are lost.
What is the electronic structure of Mg and Mg²⁺?
Mg: 1s² 2s² 2p⁶ 3s²; Mg²⁺: 1s² 2s² 2p⁶.
What happens when a negative ion is formed?
Electrons are gained.
What is the electronic structure of O and O²⁻?
O: 1s² 2s² 2p⁴; O²⁻: 1s² 2s² 2p⁶.
