Atom of chemical element consists of a kernel and electrons. The quantity of electrons in atom depends on its atomic number. The electronic configuration determines distribution of an electron by covers and subshells.
It is required to you
- Atomic number, structure of a molecule
Instruction
1. If atom elektroneytralen, then the number of electrons is equal in it to number of protons. The number of protons corresponds to atomic number of an element in Mendeleyev's table. For example, hydrogen has the first atomic number therefore its atom has one electron. Atomic number of sodium - 11 therefore atom of sodium has 11 electrons.
2. Atom can also lose or attach electrons. In this case atom becomes the ion having electric positive or negative charge. Let's say one of electrons of sodium left an electron shell of atom. Then atom of sodium will become the positively charged ion having a charge of +1 and 10 electrons on the electron shell. At accession of electrons, atom becomes a negative ion.
3. Atoms of chemical elements can also connect in molecules, the smallest particle of substance. The quantity of electrons is equal in a molecule to quantity of electrons of all atoms entering it. For example, the molecule of H2O water consists of two atoms of hydrogen, each of which has on one electron, and atom of oxygen which has 8 electrons. That is, in a molecule of water of only 10 electrons.