Answer:
3 atoms
Explanation:
it contains 2 atoms of hydrogen(H) and 1 atom of oxygen(O). So in total there are 3 atoms.
Answer:
2.5 g mass of Ra-226 will remain after 4800 years.
Explanation:
Given data:
Mass of Ra-226 = 20 g
Sample remain after 4800 years = ?
Solution:
Half life of Ra-226 = 1600 years
Number of half lives passed = T elapsed / half life
Number of half lives passed = 4800 year / 1600 year
Number of half lives passed = 3
At time zero = 20 g
At first half life = 20 g/2 = 10 g
At 2nd half life = 10 g/2 = 5 g
At 3rd half life = 5 g/2 = 2.5 g
Thus, 2.5 g mass of Ra-226 will remain after 4800 years.
Answer:
Charles Darwin
Explanation:
Charles Darwin is more famous than his contemporary Alfred Russel Wallace who also developed the theory of evolution by natural selection. scientist who studies living organisms.J
Answer:
C2H2 + 5 O2 = 4 CO2 + 2 H2O
Add / Edited: 27.09.2014 / 25.01.2015
Evaluation of information: 5.0 out of 5 / number of votes: 2
Source: https://chemiday.com/en/reaction/3-1-0-339
Explanation:
A compound was found to be soluble in water. It was also found that addition of acid to an aqueous solution of this compound resulted in the formation of carbon dioxide. Which one of the following cations would form a precipitate when added to an aqueous solution of this compound?
Options
a. NH4
b. K
c. Cr
d. Rb
e. Na
Answer: c: Cr
Explanation:
The aforementioned reaction are banters for to distract ones focus from the question.
However it should be noted that
Cr can be found in tannery waste water showing that it can be soluble in water.
The carbonate compound when reacting with acid CO_2 evolves.
Focusing on the cation that would form a precipitate when added to an aqueous solution.
Chemical precipitation method is a common method for to remove chromium and to recover it from tannery wastewater.
Cr would form a precipitate.
