Answer:
John Dalton is the correct answer.
Explanation:
Answer:
KNO2, KBr
Explanation:
Chemical compounds are any substance composed of identical molecules consisting of atoms of two or more chemical elements. So NO2 and KBr are compounds, Br2 and Fe are not.
The reactants are the substances on the left side, which react and give the products on the right side.
The reactants are Fe and O.
The product is Fe2O3.
The arrow to the right means that the reaction is going in only one direction — the only reaction happening at the moment is that Fe and O are making Fe2O3.
(s) means the substance is in the solid state, and (g) means in a gaseous state (or the substance is a gas in that reaction).
Answer:
Explanation:
Matter is anything that has weight and occupies space.
To prove that a bicycle is a matter, we need to show that it has weight and will occupy space.
When you put the bicycle on a weighing scale, you will see the weight of the bicycle. This a proof that bicycle is a matter.
To show that the bicycle can occupy space, place the device in a tank full of water. From the tank, the bicycle will displace some water. Substances that cannot occupy space will not behave in such manner.
Answer:
b. 3.66x10²³ atoms of chromium.
Explanation:
First we calculate how many moles are there in 31 grams of chromium, using its molar mass:
- Molar Mass of Chromium = 51 g/mol (This can be found on any periodic table)
- 31 g ÷ 51 g/mol = 0.608 mol
Then we <u>calculate how many atoms are there in 0.608 moles</u>, using <em>Avogadro's number</em>:
- 0.608 mol * 6.023x10²³ atoms/mol = 3.66x10²³ atoms
The correct answer is thus option b. 3.66x10²³ atoms of chromium.
