Unit 1 AoS1- The Periodic Table Flashcards
(49 cards)
Define excited state.
The excited state is the state of an atom, ion, etc. in which one or more electrons have absorbed energy and are not in their lowest energy levels.
What does the Law of Conservation of Mass state?
The law of conservation of mass states that during a chemical reaction, the mass of the reactants must equal to the mass of the products.
Define ground state.
The ground state is a term used to describe atoms in which the elections are in their lowest possible energy levels.
What are the sub- atomic particles?
Protons, neutrons and electrons.
What are isotopes?
Isotopes are atoms with the same atomic number but different mass numbers, therefore they have a varying number of neutrons.
Who discovered the neutron?
James Chadwick
Who is responsible for the discovery of the nucleus and the protons within it, and through what experiment was this discovery based on?
Ernest Rutherford discovered this through the Gold Foil experiment.
Who discovered the electron and through what experiment was the discovery based on?
J.J Thompson discovered the electron through the cathode ray experiment.
Who was the scientist who proposed an early atomic model and what was the name of this model?
J. J Thompson designed the plum pudding model where he concluded that atoms consist of a sphere of positive matter in which electrons were embedded randomly like plums in a pudding.
What is ionization energy?
It is energy required for the removal of an electron from the outer shell of a gaseous atom.
What does it mean if an atom has lower ionization energy?
Lower ionization energy makes it easier to remove the valence electron.
What are the four subshells, in order?
S, P, D, F
What are lanthanides?
The set of elements with atomic numbers from 58 and 71, in which the 4f-subshells are progressively being filled.
What are actinides?
The set of elements with atomic number between 90 and 103, in which the 5f-subshells are progressively filled.
First ionization is governed by what 4 factors?
1) the charge on the nucleus
2) the distance of the outer electron from the nucleus
3) the amount of screening by inner electrons
4) location of the electron being removed in terms of its orbital and how many electrons are present in that orbital
Going down the periodic table groups, what happens to the ionization energy?
There is a drop in ionization energy.
Going across the periodic table periods, what happens to the ionization energy?
The ionization energy increases, making it harder to remove the outer electron.
What is the second ionization energy?
It is the energy needed to remove a second electron from each ion in 1 mole of gaseous +1 ions to give gaseous +2 ions.
How do you find the group of an element using the successive ionization energies?
The big gap between two successive ionization energies is typical of removing an election from the inner energy level, therefore from the successive ionization, it can be figured out what group the element is from.
What are the two exceptional electronic configurations?
Cr (24) has an electronic configuration of 4s1, 3d5 in order to gain a half-filled stable d-subshell configuration and Cu (29) has an electronic configuration of 4s1, 3d10 in order to gain a full-filled stable d-subshell configuration.
What is the modern periodic table based on and why does it not follow Mendeleev’s periodic law?
The modern periodic table is based on atomic number because atomic weight is not a good parameter to distinguish between two elements due to isotopes.
What is Mendeleev’s periodic law?
Mendeleev proposed that the properties of elements vary periodically with their atomic weights.
What is a combination reaction?
2 or more reactants join to form a compound.
What is a decomposition reaction?
The breakdown of a reactant into 2 or more products.
