All chemical reaction between substances results into a chemical change. When two substances just like HCL and NaOH reacts with each other, NaCl means Sodium Chloride salt is formed.
The phenomenon like change in color, change in temperature, release of gas etc when happens ,then it means chemical change has been occurred. e.g
HCl +NaOH ----> NaCl +H2O.
Moles of Ammonia produced : 4 moles
<h3>Further explanation</h3>
Given
6 mol of H₂
Required
moles of Ammonia
Solution
Reaction
N₂ + 3H₂ → 2NH₃
In chemical equations, the reaction coefficient shows the mole ratio of the reacting compound (reactants and products)
From the equation, mol ratio of H₂ : NH₃ = 3 : 2, so mol NH₃ :
= 2/3 x moles H₂
= 2/3 x 6
= 4 moles
Answer:
cells arose from preexisting cells
Explanation:
<em>Rudolph Virchow is a German biologist that built on the work of other scientists such as Theodor Schwan to contribute his own quota to the development of the cell theory as it is currently known.</em>
After several studies, Virchow rejected the idea of spontaneous generation and accepted the initially rejected idea of cell division. He earlier believed that cell division only takes place is some special type of cells and not in all cells.
Even though Virchow was not the first to bring the idea of cells arising from preexisting cells, he was the one that popularized the idea and added it to the earlier belief that all living organisms are made up of cells.
<u>Answer:</u> The age of the mineral sample is 
<u>Explanation:</u>
The equation used to calculate rate constant from given half life for first order kinetics:

where,
= half life of the reaction = 
Putting values in above equation, we get:

We are given:
Mass ratio of K-40 to Ar-40 = 0.812 : 1.00
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = ? yr
= initial amount of the sample = [1.00 + 0.812] = 1.812 grams
[A] = amount left after decay process = 1.00 grams
Putting values in above equation, we get:

Hence, the age of the mineral sample is 