An element with 8 valence electrons is Neon (Ne).
Ps: Any element under group 18 has 8 valence electrons except for Helium (He).
Answer:
The reaction is B. Synthesis
Explanation:
In the case of this reaction, it corresponds to a synthesis where 2 compounds (calcium oxide and water) are combined to form a new one (calcium hydroxide).
Answer:

Explanation:
Given :
Mass of a bar of lead = 115.2 g
Initial water level
= 25 mL
Final water level
= 35.5 mL
Difference in the water level = 35.5 - 25
= 10.5 mL
= 
We know that when a body is submerged in water, it displaces its own volume of water.
Therefore, the volume of the lead bar = volume of the water displaced = 10.5 mL = 
We know that mathematically, density is the ratio of mass of body to its volume.
Density of the lead bar is given by :


= 
Answer:
0.559 L
Explanation:
Step 1: Given data
- Moles of sodium iodide (n): 0.405 mol
- Molar concentration of sodium iodide (M): 0.724 M (0.724 mol/L)
Step 2: Calculate the volume of solution (V)
The molarity is equal to the moles of solute divided by the liters of solution.
M = n/V
V = n/M
V = 0.405 mol/(0.724 mol/L) = 0.559 L
<h3><u>Answer;</u></h3>
Nitrogen (N)
<h3><u>Explanation;</u></h3>
- Atoms may lose or gain electrons to achieve stability. Metal atoms lose electrons to attain stable configuration, and as a result they form positively charged ions called cations.
- <u>Non-metals on the other hand gain electrons to attain stable configuration, and as a result form negatively charged ions called anions.</u>
- <u>Among the elements given above nitrogen (N) gains electrons to form a negatively charged ion called anion. </u>