Answer:
20 atoms
Explanation:
There are 4 in H2O2 because of 2 hydrogens and 2 oxygens.
Then, multiply by 5 because the coefficient is 5, therefore there are 5 H2O2 molecules.
5 x 4 = 20
Explanation:
The sum of total number of protons present in an element is known as atomic number of the element.
- As atomic number of Cs is 55.
And, it is known that for a neutral atom the number of protons equal to the number of electrons.
Since, no charge in present on given Cs atom it means that it is neutral in nature. Hence, number of protons and electrons present in Cs are 55.
- For Ba, it is also neutral in nature and atomic number of barium is 56. Hence, number of protons and electrons present in Ba are 56.
- For S, there is no charge on it so it is also neutral in nature. Atomic number of S is 16. Hence, number of protons and electrons present in S are 16.
Answer: A. uranium salt
Becquerel made a conclusion that it was the uranium that causes the images found in the photographic plates. Though his theory was disproved during the first time,he continued to develop it. Then, it is through this experiment that Becquerel discovered radioactivity.
Answer:
- <u><em>0.80 mol Al</em></u>
Explanation:
<u>1) Word reaction:</u>
- Aluminum + ferrous oxide → aluminum oxide + iron
This is a single replacement reaction, in which aluminum, a more acitve metal than iron, replaces the iron in the ferrous oxide to form aluminum oxide and iron.
<u>2) Skeleton chemical equation:</u>
<u>3) Balanced chemical equation:</u>
Add the coeffcients to comply with the law of conservation of mass:
<u>4) Mole ratio of Al and FeO:</u>
<u>5) Set a proportion with the unkown and solve:</u>
- x / 1.2 mol FeO = 2 mol Al / 3 mol FeO
- x = 1.2 mol FeO × 2 mol Al / 3 mol FeO =<u> </u><u>0.80 mol Al ← answer</u>
