Answer:
En total son 8 modelos, en la explicación los nombraremos por orden de antigüedad.
Explanation:
Modelo atómico de Demócrito (450 a.C.)
Modelo atómico de Dalton (1803 d.C.)
Modelo atómico de Lewis (1902 d.C.)
Modelo atómico de Thomson (1904 d.C.)
Modelo atómico de Rutherford (1911 d.C.)
Modelo atómico de Bohr (1913 d.C.)
Modelo atómico de Sommerfeld (1916 d.C.)
Modelo atómico de Schrödinger (1926 d.C.)
Calcium reacts gently with water to give hydrogen and calcium hydroxide, which is only slightly soluble, thus slows down the reaction.
It will be assumed that hydrochloric acid used is a dilute aqueous solution.
However, calcium reacts with hydrochloric acid to give calcium chloride which is readily soluble in water, and hydrogen, being a typical reaction of relatively active metals with acids.
Ca(s) + 2HCl(aq) -> CaCl2(aq) +H2(g) ↑ + heat
The clues that it is a chemical reaction could be:
- formation of a new substance, gaseous hydrogen
- disappearance of a metallic solid in the solution
- heat formed during the vigorous reaction.
As silver is below hydrogen in the electrochemical series, it will not be expected to react with dilute hydrocloric acid. (however, it dissolves in oxidizing acid such as nitric acid, but not displacing hydrogen as a product).
Answer:
Saturn's orbit is 29.5 "Earth years" and if Saturn's four seasons last an equal amount of time, the approximate length would be 29.5 / 4
29.5 / 4 = 5.9
So each season on Saturn is 5.9 "Earth years" Long.
Answer is: 1035 joules of heat is needed.<span>
m(substance</span>) = 75 g.<span>
ΔT(substance</span>)
= 15°C.<span>
cp(substance</span>)
= 0,92 J/g°C.<span>
Q = m</span>(substance) · ΔT(substance) · cp(substance).<span>
Q = 75 g · </span>15°C · 0,92 J/g°C<span>.
Q = 1035 J = 1,035 kJ.</span>
