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The first twenty elements of the periodic table

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The first twenty elements of the periodic table

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all matter can be classified as a mixture of substances or a pure substance.

Pure substances can be further classified as elements or compounds

What is a compound ?
A compound is atoms of two or more different kinds are chemically bonded in some fixed ratio.

What is a mixture ?
Mixtures are combinations of two or more elements and/or compounds.

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The nucleus -
This is the middle of the atom and consists of protons and neutrons. Electrons fly around the nucleus.

Neutrons -
These are in the nucleus and are not positively or negatively charged they are just neutral.

Electrons -
These are negatively charged and fly around the nucleus.

Protons -
These are positively charged are located inside the nucleus

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Atoms are made up of a nucleus, protons and electrons.

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Information about the first twenty elements

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Information about the first twenty elements

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Hydrogen -
Hydrogen is a chemical element with symbol H and atomic number 1. With a standard atomic weight of 1.008, hydrogen is the lightest element on the periodic table. It is in group 1. Sign : H

Helium -
Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the elements. It is in group 8. Symbol: He

Lithium -
Lithium is a chemical element with symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the lightest metal and the lightest solid element. In group 1. Symbol: Li

Beryllium -
Beryllium is a chemical element with symbol Be and atomic number 4. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays. It is in group 2.

Boron -
Boron is a chemical element with symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is a low-abundance element in the Solar system and in the Earth's crust. It is in group 3. It's symbol is B

Carbon -
Carbon (from Latin: carbo "coal") is a chemical element with symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It is in group 4. It's symbol is C.