Answer:
The two observations we made from viewing the solar system model are as follows as:
1). When we look at the sky we observe that the motions of all the planets and the stars are perfect circular movements with a good and high speed, but not in velocity because in velocity direction doesn't charges.
2). The sun is at the centre of our solar system and all the planets are equidistant to each other planets and also revolve around the sun.
Answer:
D
Explanation:
31 / 2.8 = 11.0714286 L per mole of helium
3.5 / 4 = 0.875 moles
2.8 + 0.875 = 3.675 moles
11.0714286 x 3.675 = 40.6875 L
Balanced chemical reaction: Ba(OH)₂(aq) → Ba²⁺(aq) + 2OH⁻(aq).
According <span>to the Arrhenius definition barium hydroxide is base.
According this theory a</span>cids are substances which produce hydrogen ions in water solution, bases are substances which produce hydroxide ions in solution. Acids and bases when react (neutralisation) produce salt and water.
Energy Levels of Electrons. As you may remember from chemistry, an atom consists of electrons orbiting around a nucleus. ... They are restricted to orbits with only certain energies. Electrons can jump from one energy level to another, but they can never have orbits with energies other than the allowed energy levels.
