3. Reading text and fill in the blanks nucleus, shell, atom,
shell, atom, neutral, negative, electrons, orbital, positive
neutron,
protons,

Scientists say that the smallest particle of substances are called Atom means indivisible
derived from atomos in Greek language because of its very small size. Atom has two parts, nucleus
and
is located in the center of atom and electrons move around nucleus with high
speed.Scientists believed that atoms were indivisible up to 20th century. Today we know that atoms
have subatomic particles, called
and electrons
Protons are
particles found in the nucleus of an atom, and shown as "p". Each element has
certain number of protons which differ from other elements. Neutrons are particles found in
the nucleus of an atom, and shown as "n". Electrons are particles that move around the
nucleus of an atom, and shown as “e". Neutral atoms have the equal number of protons and
electrons. Electrons are rotating in certain places called
energy level or shell. The electrons
located in the outermost shell of atoms are called
have the same number of
protons but different number of neutrons.They have similar chemical properties but different
physical properties.​

andreyBublik    2   12.03.2021 19:00    4