Lithium (Li)
Lithium is the lightest metal and the least dense solid element, light enough to float on water.
Lithium properties
- Atomic mass
- 6.94 u
- Category
- Alkali metal
- Group
- 1
- Period
- 2
- Block
- s-block
- State at room temp.
- Solid
- Electronegativity
- 0.98
- Melting point
- 453.65 K (180.5 °C)
- Boiling point
- 1,603 K (1,329.8 °C)
- Density
- 0.534 g/cm³
- Atomic radius
- 182 pm
- Ionization energy
- 5.392 eV
- Electron affinity
- 0.618 eV
- Radioactive
- No, has stable isotopes
- Discovered
- 1817
Lithium electron configuration
- Electron configuration
- [He] 2s1
- Full electron configuration
- 1s2 2s1
- Electron shells
- 2 · 1
The electron configuration of Lithium (Li) is [He] 2s1. Its 3 electrons are arranged in shells as 2, 1.
Protons, neutrons and electrons in Lithium
A neutral Lithium atom has 3 protons and 3 electrons. Most Lithium atoms have about 4 neutrons: the atomic mass rounded to 7, minus the atomic number 3.
Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass
How many valence electrons does Lithium have?
1
Lithium has 1 valence electron in its outermost shell, shell 2. These are the electrons involved in chemical bonding.
Lithium orbital diagram
Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations
Molar mass of Lithium
6.94 g/mol
One mole of Lithium atoms (6.022 × 10²³ atoms) has a mass of 6.94 grams. Use this value to convert between grams and moles.
Compounds containing Lithium
Lithium facts
- Lithium is the lightest metal and the least dense solid element, light enough to float on water.
- Lithium's name comes from the Greek word lithos, meaning 'stone', because it was discovered in a mineral rather than in plant or animal material.
- Lithium (Li) has atomic number 3 and is a solid at room temperature. It was discovered in 1817.
Position in the periodic table
Lithium is element 3, in period 2 and group 1 of the periodic table, in the s-block.
Uses of Lithium
Lithium's most important use today is in rechargeable lithium-ion batteries for phones, laptops and electric cars. Lithium compounds are also added to heat-resistant glass and ceramics, such as glass-ceramic cooktops, and to greases that keep working over a wide temperature range. Lithium carbonate is a long-established medicine for bipolar disorder, and aluminum-lithium alloys make aircraft parts lighter.
Who discovered Lithium?
Johan August Arfwedson discovered lithium in 1817 while analyzing the mineral petalite in Jöns Jacob Berzelius's laboratory in Stockholm. The metal itself was first isolated in 1821 by William Thomas Brande, using electrolysis.
Where does the name come from?
Lithium comes from the Greek lithos, meaning 'stone'. Jöns Jacob Berzelius chose the name to reflect its discovery in a solid mineral, petalite, whereas potassium had been found in plant ashes.
Same group
Compare Lithium
FAQ
What is the electron configuration of Lithium?
The electron configuration of Lithium (Li) is [He] 2s1. Its 3 electrons are arranged in shells as 2, 1.
How many protons, neutrons and electrons does Lithium have?
A neutral Lithium atom has 3 protons and 3 electrons. Most Lithium atoms have about 4 neutrons: the atomic mass rounded to 7, minus the atomic number 3.
How many valence electrons does Lithium have?
Lithium has 1 valence electron in its outermost shell, shell 2. These are the electrons involved in chemical bonding.
What is the molar mass of Lithium?
The molar mass of Lithium is 6.94 g/mol. This is the same number as its atomic mass, 6.94 u.
Is Lithium a metal?
Yes. Lithium is an alkali metal, so it is a metal.
Is Lithium radioactive?
Ordinary Lithium is not radioactive: it has at least one stable isotope. Like every element, it also has radioactive isotopes, most of them made in laboratories.
Where is Lithium on the periodic table?
Lithium is element 3, in period 2 and group 1 of the periodic table, in the s-block.