Science / Chemistry / Beryllium: (Be) Element 4, atomic weight 9.0122, an extremely toxic metal used as a neutron source and in phosphors.

Beryllium (Be)

Science / Periodic Table of Elements / Beryllium (Be): Atomic number: 4, Atomic mass: 9.01218 g.mol -1, Electronegativity: 1.5, Density: 1.86, Melting point: 1280 °C, Boiling point: 2970 °C, Vanderwaals radius: unknown, Ionic radius: unknown, Iso MORE

Aneroid Barometer

Science / Weather / Aneroid Barometer: An instrument for measuring the atmospheric pressure. It registers the change in the shape of an evacuated metal cell to measure variations on the atmospheric pressure. The aneroid is a thin-walled me MORE

Radium (Ra)

Science / Periodic Table of Elements / Radium (Ra): Atomic number: 88, Atomic mass: 226.0254 g.mol -1, Electronegativity: 0.9, Density: 5 at 20°C, Melting point: 700 °C, Boiling point: 1140 °C, Vanderwaals radius: 0.230 nm, Ionic radius: unkn MORE

Polonium (Po)

Science / Periodic Table of Elements / Polonium (Po): Atomic number: 84, Atomic mass: (210) g.mol -1, Electronegativity: 2.0, Density: 9.51 at 20°C, Melting point: 254 °C, Boiling point: 962 °C, Vanderwaals radius: 0.164 nm, Ionic radius: 0.102 MORE

Alkaline Earth Metal

Science / Chemistry / Alkaline Earth Metal: (alkali metal) The Group 2 elements, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra) form alkaline oxides and hydroxides and are called 'alkaline earth metal MORE

Calcium (Ca)

Science / Periodic Table of Elements / Calcium (Ca): Atomic number: 20, Atomic mass: 40.08 g.mol -1, Electronegativity: 1.0, Mass volume: 1.6 at 20°C, Melting point: 840 °C, Boiling point: 1484 °C, Vanderwaals radius: 0.197 nm, Ionic radius: 0 MORE