This is the property used to arrange elements in the modern periodic table.
What is atomic number?
This is the energy required to remove one mole of electrons from one mole of gaseous atoms.
What is first ionisation energy?
A measure of the attraction an atom involved in a bond has for the bonding electrons.
What is electronegativity?
The intermolecular forces that arise from temporary dipoles and induced dipoles caused by movement of electrons.
What are London dispersion forces?
A molecule that possesses a permanent dipole.
What is a polar molecule?
Elements in the same group have this feature in common.
What is the same number of outer shell electrons?
First ionisation energy generally increases across a period because atomic size ______.
What is decreases?
The electronegativity increases
hat happens to electronegativity across a period?
The strength of London dispersion forces increases as this property of an atom or molecule increases.
What is the number of electrons?
Hydrogen bonding produces an expanded/open structure in ice, increasing the volume and reducing the density.
Why is ice less dense than liquid water?
Across a period, covalent radius generally does this.
What is decreases?
This effect reduces the attraction between the nucleus and outer electrons.
What is the screening effect?
Nuclear charge, covalent radius and screening by inner-shell electrons.
What factors affect electronegativity?
The additional electrostatic attraction between molecules that possess permanent dipoles.
What are permanent dipole-permanent dipole interactions?
A substance has a low boiling point and does not conduct electricity. Deduce its structure.
What is simple molecular (covalent molecular)?
The decrease in atomic size across a period is due to increasing ______.
What is nuclear charge?
Ionisation energy generally decreases down a group because of increased shielding and larger ______.
What is atomic radius?
A bond between atoms with different electronegativities is described as this.
What is polar covalent?
An electrostatic attraction between molecules containing H bonded directly to F, O or N.
What is hydrogen bonding?
This type of substance tends to dissolve in water.
What are ionic or polar substances?
This causes the reduction in nuclear charge going down a group
What is the screening (shielding) effect?
The second ionisation energy is always greater than the first because, after the first electron has been removed, the remaining electrons experience a stronger attraction to the nucleus.
Why does the second ionisation energy require more energy than the first?
The notation δ+ and δ− is used to show these on atoms in a polar covalent bond.
What are partial charges?
Hydrogen bonding occurs when hydrogen is bonded to one of these three elements.
What are fluorine, oxygen and nitrogen?
This phrase summarises solubility behaviour.
What is "like dissolves like"?