Incorrect test questions

Incorrect test questions

1. Electrons

   • An electron is a negatively charged subatomic particle. It can be either free (not attached to any atom), or bound to the nucleus of an atom. Electrons in atoms exist in spherical shells of various radii, representing energy levels.

2. protons

   • A proton is a subatomic particle found in the nucleus of every atom. The particle has a positive electrical charge, equal and opposite to that of the electron. If isolated, a single proton would have a mass of only 1.673 ? 10-27 kilogram, just slightly less than the mass of a neutron.

3. neutrons

   • Neutrons are the particles in an atom that have a neutral charge. They aren't positive like protons.

4. relative charges and masses

   • t is well known that an electron has -1.602 x 10^-19 Coulombs of charge and a proton has +1.602 x 10^-19 Coulomb.We can say that these are absolute values of charge.However, to simplify the things if we say that an electron has -1 unit charge then proton will have +1 unit charge.These numbers are then called relative charges

5. mass number and atomic number

   • the number of protons in the nucleus of an atom, which is characteristic of a chemical element and determines its place in the periodic table.
   • It is identical to the charge number of the nucleus. The atomic number uniquely identifies a chemical element. In an uncharged atom, the atomic number is also equal to the number of electrons. The sum of the atomic number Z and the number of neutrons, N, gives the mass number A of an atom.

6. chemical symbols

   • The elements of the periodic table sorted by symbol The chemical elements of the periodic chart sorted by: Symbol Name chemical element - Electronegativity Ar Argon - Density As Arsenic - Melting point At Astatine - Boiling point Au Gold