Answer:
:0
Explanation:
One second after the Big Bang, the universe was filled with neutrons, protons, electrons, anti-electrons, photons and neutrinos.Jun 17, 2017
Molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.
While Atoms are single neutral particles,
Molecules are neutral particles made of two or more atoms bonded together.
Exaplmes for molecules
H2O (water)
N2 (nitrogen)
O3 (ozone)
CaO (calcium oxide)
C6H12O6 (glucose, a type of sugar)
NaCl (table salt
And examples for atoms
Neon (Ne)
Hydrogen (H)
Argon (Ar)
Iron (Fe)
Calcium (Ca)
Deuterium, an isotope of hydrogen that has one proton and one neutron.
Plutonium (Pu)
F-, a fluorine anion.
There are two valence electrons.
It's 1. Melting a substance. The rest are chemical changes
Answer : Broadly solids are divided into three categories;
i) Crystalline solids have a regular definite structure, in which the particles pack in a repeating pattern from one edge of the solid to the other.
ii) Amorphous solids have a random structure, with little unorganized pattern long-range order.
iii) Polycrystalline solids are those where an aggregate which consists of a large number of small crystals or grains in which the structure is regular, but the crystals or grains are found to be arranged in a random fashion.
Also solids can be divided into 3 more categories according to their bonds;
i) Covalent solids, like diamond, which forms crystals that can be viewed as a single giant molecule made up of an almost endless number of covalent bonds.
ii) Ionic solids are basically salts, such as NaCl, in which the molecules are held together by the strong force of attraction between ions of opposite charge.
iii) Metallic solids are found in metals which have the force of attraction between atoms of metals, such as copper and aluminum, or alloys, such as brass and bronze, are metallic bonds.