Elements of Life

Why does the atomic emission spectra converge at high frequencies.

As energy levels increase, they gradually get closer together. Therefore, jumps from high energy levels will produce similar similar frequencies of light and cause the lines to be close together in the spectrum.

Isotope

Atoms with the same atomic number but different mass number (number of protons) but different mass numbers(number of neutrons).

Appearance of Atomic Absorption Sectrum

Black lines on a bight coloured background. Lines occur in series and converge at high frequencies.

Appearance of Atomic Emission Spectra

Bright coloured lines on a black background.

Why do the lines in an atomic emission spectrum occur in series?

Electrons drop to lower energy levels which emits light energy. Several transitions occur to the same energy level which forms a series of lines. Eg. all drops to n=1 will produce a series of lines.

Why is the atomic emission spectra unique to a particular element?

Elements have different patterns of energy levels so electrons emit different levels of light energy when they drop to lower levels. The relationship is shown as E=hv

What is an orbital?

Region of space that is occupied by 2 electrons.

What is the difference between the shape of an s-orbital and a p-orbital

S-orbitals are spherical and p-orbital have 2 lobes.

First Ionisation Enthalpy

The energy required to remove 1 mole of electrons from 1 mole of gaseous atoms, forming 1 mole of gaseous 1+ ions.

Relative Isotopic Mass

The mass of one atom of an isotope compared to 1/12 of the mass of one atom of carbon-12.

What is empirical formula?

The smallest possible ratio of elements in a compound.

Relative Atomic Mass

The weighted average of the relative isotopic masses for the naturally occurring isotopes of the element.

Shape of a water molecule and it's bond angle.

V - shaped and 104.5° as it has 4 electron pairs but 2 lone pairs.

What causes lines in an atomic emission spectra?

When a sample is heated, electrons are excited up to higher energy levels. They drop down to a lower energy level and releases energy in the form of visible light.

What causes the lines in an atomic absorption spectrum.

When light is passed through a gaseous sample, electrons will absorb the light energy in order to be excited to higher levels.

Nuclear Fusion

When the nuclei of two atoms collide and fuse to make one heavier nucleus.