physical sci: 3rd periodical

When an element has two.or more "versions" of atoms, each will have the same number of protons but different number of neutrons; the unlike versions of the atoms are called?

isotopes

refers to the amount of time it takes for half of a sample of a radioisotope to decay into a more stable form.

Half-life

Who discovered the 3 different types of radiation?

Ernest Rutherford

5 different types of radiation:

1. Alpha Emission

2. Beta Emission

3. Positron Emission

4. Electron Capture

5. Gamma Emission

The radioactive forms of elements are referred to as ?

radionuclides

atoms that are bonded together form

molecules

building blocks of matter in the universe

molecules

In a molecule, the ability of an atom to attract an electron pair in that bond is known as

electronegativity

the large electronegativity difference between the atoms in HF leads to a __ where the molecule has a dipole moment

polar covalent bond

are attractive forces between molecules or particles in the solid or liquid states.

intermolecular forces

hold atoms together in a molecule

intramolecular forces

weak electrostatic forces that attract neutral molecules to one another

intermolecular forces

intermolecular forces of attraction are collectively known as

Van der Waals forces

intermolecular forces of attraction

1. Dipole-dipole interaction

2. Hydrogen bonding

3. Ion-dipole interation

4. London dispersion forces

5. Dipole-induced dipole interaction

refers to the formation of a positive pole and negative pole of a molecule.

Dipole

form when atoms share electrons unequally, making one atom partially negative (-) and the other partially positive (+).

Polar molecules

exist between polar molecules. One end of a dipole attracts the oppositely charged end of the dipole

Dipole-dipole forces

It is a special and very strong type of dipole-dipole force that exists between a hydrogen atom bound to a small and highly electronegative non-metal atom

Hydrogen Bonding

It is stronger force than dipole-dipole and dispersion forces.

Hydrogen Bonding

It acts between an ion (either positive or negative) and a polar molecule.

Ion-Dipole Force

This explains the solubility of ionic compounds in water which is polar molecule.

Ion-Dipole Force

• The ions and the oppositely charged ends of the polar water molecules overcome the attraction between ions themselves.

• Each ion becomes separated and water molecules cluster around it

Ion-Dipole Force

• The weakest type of intermolecular force.

• When two non-polar molecules approach each other, an instantaneous dipole moment forms.

London-Dispersion Forces

London-Dispersion Forces is sometimes called an?

n induced dipole-induced dipole attraction

Interaction between polar and non-polar molecules.

Dipole-Induced Dipole Forces

• has an equal distribution of electrons throughout the molecule.

• have either a negative or a positive pole.

Non-polar molecule

General Properties of Liquids

1. Surface Tension

2. Viscosity

3. Vapour Pressure

4. Boiling Point

5. Heat of Vaporization

6. Capillary Action

• It is the measure of the elastic force in the surface of a liquid.

• It is the amount of energy required to stretch or increase the surface of a liquid by a unit area.

• It is manifested as some sort of skin on the surface of a liquid or in a drop of liquid.

Surface Tension

the tendency of a liquid to rise in narrow tubes or be drawn into small opening as such as those between grains of a rock.

Capillary Action

Two types of forces are involved in capillary action:

1. Cohesion

2. Adhesion

the intermolecular attraction between liquid-liquid (like molecules).

Cohesion

the attraction between solid-liquid (unlike molecules).

Adhesion

depends on their intermolecular attraction

Viscosity

It is the pressure exerted by its vapor when in equilibrium with liquid or solid.

Vapor pressure

is the temperature at which its vapor pressure is equal to the external or atmospheric pressure.

Boiling point

is the amount of energy required to vaporize one mole of a liquid.

molar heat of vaporization