Answer:
potassium
The third alkali metal is K (potassium). The atomic number of K (potassium) is 19. Thus, the atomic number of third alkali metal is 19
Explanation:
Answer:- Density is 10.5 grams per mL and the substance is Silver(Ag).
Solution:- Mass of jewelry is given as 132.6 g. Initial volume of water in the graduated cylinder is 48.6 mL and the volume becomes 61.2 mL when this jewelry is submerged in the cylinder.
So, the volume of the jewelry = 61.2 mL - 48.6mL = 12.6 mL
We know that, 
Let's plug in the values in the above formula to calculate the density:


So, the density of the jewelry is
.
The substance from which the jewelry is made could easily be identified by comparing the calculated density with the density values given for different substances in the density table.
Looking at the density table, 10.5 grams per mL is the density for silver. So, the jewelry is made up from Silver.
The answer is 33.2 moles of a solute is present in 4.00 L of an 8.30 M solution , Option A is correct .
<h3>
What is Molarity ?</h3>
Molarity is defined as the amount of solute (in moles)in per litre of solution.
It is also known as molar concentration of a solution , It is expressed in mol/l

We can rearrange this equation to get the number of moles:
n= M * V
The molarity of solution is 8.3 M and the volume given is 4 litres
the moles will be n = 8.30 * 4 = 33.2 moles
Therefore 33.2 moles of a solute is present in 4.00 L of an 8.30 M solution , Option A is correct .
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Answer:
A. It shows the same number of atoms of each element on both sides of the equation.
Explanation:
A balanced chemical equation demonstrates the conservation of matter by showing the number of atoms of each element on both sides of the equation or expression.
According to the law of conservation of matter, matter is neither created nor destroyed in the course of a chemical reaction but atoms are rearranged.
- Based on this premise, the number of atoms or moles on both sides of the expression must be equal.
- If there are 3 atoms of carbon on one side, the product must also reflect 3 atoms of carbon.