Answer: 406 hours
Explanation:
where Q= quantity of electricity in coloumbs
I = current in amperes = 39.5 A
t= time in seconds = ?
The deposition of copper at cathode is represented by:
Coloumb of electricity deposits 1 mole of copper
i.e. 63.5 g of copper is deposited by = 193000 Coloumb
Thus 19.0 kg or 19000 g of copper is deposited by = 
Coloumb
(1hour=3600s)
Thus it will take 406 hours to plate 19.0 kg of copper onto the cathode if the current passed through the cell is held constant at 39.5 A
Answer:
All living things are made up of cells.
cells are the basic unit of structure and function of ll living things.
All cells are come from other cells.
Explanation:
The cell theory is historic scientific theory and is universally accepted. This theory was given by Robert Hook in 1665. According to this theory all living things are made up cells.
Cell:
Cell is the smallest unit of life and it is building block of life.
This theory consist of following points:
All living things are made up of cells.
Cells are the basic unit of structure and function of ll living things.
All cells are come from other cells. Which means that cells are originated from pre-existing cells.
The other given options:
Cells comes from nonliving matter.
Cells make up most organisms bu not all.
These are two are not the postulate of cell theory because all living organisms are made of cells.
The fraction of the original amount remaining is closest to 1/128
<h3>Determination of the number of half-lives</h3>
- Half-life (t½) = 4 days
- Time (t) = 4 weeks = 4 × 7 = 28 days
- Number of half-lives (n) =?
n = t / t½
n = 28 / 4
n = 7
<h3>How to determine the amount remaining </h3>
- Original amount (N₀) = 100 g
- Number of half-lives (n) = 7
- Amount remaining (N)=?
N = N₀ / 2ⁿ
N = 100 / 2⁷
N = 0.78125 g
<h3>How to determine the fraction remaining </h3>
- Original amount (N₀) = 100 g
- Amount remaining (N)= 0.78125 g
Fraction remaining = N / N₀
Fraction remaining = 0.78125 / 100
Fraction remaining = 1/128
Learn more about half life:
brainly.com/question/26374513
Water and carbon dioxide respectively
