It was first isolated in 1808 in England when Sir Humphry Davy electrolyzed a mixture of lime and mercuric oxide.

Calcium was named after the Latin term calx meaning lime, and is a reactive silvery metallic element found in Group 2 of the periodic table. The total number of particles in the nucleus ( protons + neutrons ). It is also the fifth most abundant dissolved ion in seawater. To take out an electron from an atom, the atom should be isolated, gaseous and neutral. An atom can have internal energy equal to any one of these values, but it cannot. Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table. Caesium is a Group $1$ element having electronic configuration as $$ is formed. The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Group $1$ elements have the property of Electro positivity, which is the tendency to lose electrons, and form positive ions. In contrast, the number of neutrons for a given element can vary. In fact, the number of protons determines what atom we are looking at (e.g., all atoms with six protons are carbon atoms) the number of protons in an atom is called the atomic number. When an atom gains an electron, it forms a negative ion known as carbanion and when an atom loses an electron, it forms a positive ion called carbocation. Atoms of each element contain a characteristic number of protons. So, atoms can only gain, lose or share electron(s). The number of protons in an atom is fixed. Hint: Group I elements are electropositive elements which means that they will from carbocations only and not carbanion to make itself stable according to octet rule.Īn atom in the ground state has an equal number of protons and electrons.

How many protons does caesium have