2) Element symbol: H
 

3) Number of electrons, protons, and neutrons: 1 electron, 1 proton, 0 neutrons
 

4) Atomic number: 1
 

5) Atomic mass: 1.00794
 

6) Characteristics:

At ordinary temperature, it is a colorless, tasteless, and odorless gas.
 

7)

History:

Hydrogen was confused with other gases until the British chemist Henry Cavendish demonstrated in 1766 that it was evolved by the action of sulfuric acid on metals and also showed at a later date it was an independent substance that combined with oxygen to form water.

In 1781, the British chemist Joseph Priestly named the gas "inflammable air." The French chemist Antoine Lauren Lavoisier renamed it hydrogen.

Three things made from the element:

- all acids contain hydrogen

- forms the essential part in all hydrocarbons

- is a component of all the constituents of living matter as well as of many minerals
 

8) Isotopes:

Deuterium; Present in ordinary hydrogen to the extent of .02%. Contains one proton and one neutron in the nucleus of each atom. Has an atomic mass of two.

Tritium; An unstable, radioactive isotope. Contains one proton and two neutrons in the nucleus of each atom. Has an atomic mass of three.
 

9) Hydrogen combines with nitrogen in the presence of a catalyst (see catalysis) to form ammonia, with sulfur to form hydrogen sulfide, with chlorine to form hydrogen chloride, and with oxygen to form water.

The reaction of oxygen and hydrogen takes place at room temperature only in the presence of a catalyst (see catalysis) such as finely divided platinum.
 

10) Hydrogen melts at -259.2 °C (-434.56 °F) and boils at -252.77 °C (-422.986 °F).