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:
molecules heat and move faster, they are moving apart. So air, like most other substances, expands when heated and contracts when cooled.
Explanation:
Because there is more space between the molecules, the air is less dense than the surrounding matter and the hot air floats upward.
You would go into negative numbers and keep subtracting.
For example, 3-4 is -1 and 4-7 is -3.
Hope you know how to do it!!!
Answer:
The number of protons in an atom define each individual element because the number of protons is the atomic number which is the defining property of an atom and never changes. The number of protons determines an atom's identity. For example, Oxygen has an atomic number of 8, so it has 8 protons, so no matter what ionic compound or molecule it's part of, every single Oxygen atom will always have 8 protons each.
