Since hydrogen only has 1 electron it shares 1 with flourine to have a pair. It is single bonded.
Radical, in chemistry, molecule that contains at least one unpaired electron. Most molecules contain even numbers of electrons, and the covalent chemical bonds holding the atoms together within a molecule normally consist of pairs of electrons jointly shared by the atoms linked by the bond.
The answer is that both models stated that Earth is the center of the system around which other objects orbit.
That is Aristotle’s model similar to Ptolemy’s model in the way that both stated that Earth is the center of the system around which other objects orbit.
Ptolemy’s model stated that Earth is the center of universe and other the sun, moon, planets, and stars revolving about it in circular orbits at increasing distance.
Aristotle’s model stated that the Sun, the Moon, the planets, and the stars travel in different separate spheres. And music of the spheres can be listen when the spheres touch each other. can be heard. He proved that the Earth is spherical,also stated that it is the the center of the universe.
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).
