Name the symbol.
Hydrogen is the most widely occurring element in the universe.
Give the atomic number.
Hydrogen is the lightest element in the periodic table and the most abundant element in the universe.
Give the atomic mass.
(2 d.p)
1.01
Hydrogen is the lightest element and consists of three isotopes - protium, deuterium, and tritium.
Identify the state under standard conditions.
Standard conditions are defined as 25.0 °C and one atmosphere pressure.
Gas
A gas is a substance that has neither a defined volume nor shape.
Give the boiling point.
(Values rounded to 4sf)
−252.9°C
−423.2°F ; 20.27 K
The boiling point is the temperature at which the surrounding pressure exerted on the liquid is equal to the opposing pressure exerted by the vapour pressure of the liquid.
Give the melting point.
(Values rounded to 4sf)
−259.2°C
−434.5°F ; 13.99 K
The melting point is the temperature at which the solid and liquid forms of a substance can exist in equilibrium.
Identify the group.
Group 1
Hydrogen is a unique element that does not fit neatly into any specific group.
It is often placed in Group 1 since it has one valence electron like the alkali metals, but it is not a metal itself.
Identify the period.
Period 1
Hydrogen is located in Period 1 of the periodic table.
Elements in this period have their first energy level occupied by electrons.
Identify the following descriptive properties of Hydrogen:
- Chemical symbol
- Atomic number
- Atomic mass
- Group
- Period
- Chemical symbol: H
- Atomic number: 1
- Atomic mass: 1.01
- Group 1
- Period 1
Identify the following physical properties of Hydrogen:
- Standard state
- Melting point
- Boiling point
- Standard state: Gas
- Melting point: −259.2°C
- Boiling point: −252.9°C
Melting: −434.5°F, 13.99 K; Boiling: −423.2°F, 20.27 K
