Elements of Life Flashcards
What is the mass and charge of a proton, neutron and electron?
Proton: mass 1, charge +1.
Neutron: mass 1, charge 0.
Electron: mass negligible, charge -1.
Describe absorption spectra.
Particles absorb emitted radiation, any analysed light is missing certain frequencies, these line appear black.
Describe emission spectra.
Particles absorbing energy are raised to higher energy states. These particles lose energy by emitting radiation. These are coloured lines on a black background.
Define atomic spectra.
Hydrogen and helium atoms are seen on an emission spectrum. The emissions and absorptions match up.
Describe Bohr’s Theory.
The electron in hydrogen only exists in certain energy levels.
A photon is emitted when an electron changes energy level.
Energy of a photon is equal to the difference between two energy levels.
What are the flame tests for Lithium, Sodium, Potassium, Calcium, Barium and Copper.
Li+ red Na+ yellow K+ lilac Ca2+ brick red Ba2+ green Cu2+ blue green
Describe an s subshell.
One s orbital, two electrons.
Describe a p subshell.
Three p orbitals, six electrons.
Describe a d subshell.
Five d orbitals, ten electrons.
Describe an f subshell.
Seven f orbitals, fourteen electrons.
Describe the trends in period 3.
Melting and boiling points increase up to Phosphorus, where they drop.
Define covalent bonding.
Two non-metals sharing electrons.
Define dative covalent bonds.
Both bonding electrons come from the same atom.
What is the bond angle in a linear molecule?
180°.
What is the bond angle in a planar molecule?
120°.
What is the bond angle in a bipyramidal molecule?
90° and 120°.
What is the bond angle in an octahedral molecule?
90°.
What is the bond angle in a tetrahedral molecule?
109.5°.
How many degrees does a lone pair remove?
2.5°.
Which ionic substances are insoluble?
Barium, calcium, lead and silver sulfates.
Silver and lead halides.
All metal carbonates.
Metal hydroxides except Group 1 and ammonium.
What colour precipitates are formed when sodium hydroxide is added to Cu2+, Fe2+ and Fe3+?
Cu2+ blue.
Fe2+ green.
Fe3+ brown.
What colour precipitate is formed when potassium iodide is added to Pb2+
Pb2+ yellow.
What colour precipitates are formed when silver nitrate is added to Cl-, Br-, and I-.
Cl- white.
Br- cream.
I- yellow.
What colour precipitate is formed when barium chloride is added to SO4^2-?
SO4^2- white.
Describe ionic bonding.
Metal and a non metal transferring electrons.
Describe group 1 and 2 trends.
More metallic down a group, less metallic across a period.
Describe ionisation enthalpy.
X(g) > X+(g) + e-.
Across a period, more atomic shielding but more protons increasing the nuclear charge.
Down a group, more atomic shielding.
Describe Group 2 reactions with oxygen, water, heat and hydroxides.
Oxygen: produces the metal oxide.
Water: forms metal hydroxide and hydrogen. Increase in reactivity down the group.
Heat: metal oxide and carbon dioxide. Thermal stability increases down the group.
Hydroxides: react with acids to make salts.
Define charge density.
Concentration of the charge on cation.
