Electron configuration
an element A has 3 shells and has 3 valence electrons
so electron configuration of A: 1s², 2s², 2p⁶, 3s², 3p¹
will tend to lose 3 electron to form a cation: A³⁺
a. Nitrate of A
A(NO₃)₃
b. Chloride of A
ACl₃
c. Oxide of A
A₂O₃
Answer:

Explanation:
We can use the Ideal Gas Law — pV = nRT
Data:
V = 66.8 L
m = 77.8 g
T = 25 °C
Calculations:
(a) Moles of N₂

(b) Convert the temperature to kelvins
T = (25 + 273.15) K = 298.15 K
(c) Calculate the pressure

Explanation:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
<u>Answer:</u> The mass of a solute is 35 grams
<u>Explanation:</u>
To calculate the mass percentage of solute, we use the equation:

Mass percent of solute = 10 %
Mass of solution = 350 g
Putting values in above equation, we get:

Hence, the mass of a solute is 35 grams