Answer:
C the number and placement of the electrons
Explanation:
Elements react with one another because they want to achieve a full valence shell of electrons. The noble gases already have a full valence shell of electrons, so they are unlikely to react with other elements.
Answer:
2.03 moles of Gold
Explanation:
Gold is one of the most precious metal metal used in many applications and mainly as a jewellery. In terms of purity it is categorized in Karats. 24 Karat is considered the purest Gold (i.e. 100 % Gold) while other Karats (14, 18, 22 e.t.c) are alloys with other metals and gyms.
Data Given:
Mass of Gold = 400 g
A.Mass of Gold = 196.97 g.mol⁻¹
Calculate Moles of Gold as,
Moles = Mass ÷ M.Mass
Putting values,
Moles = 400 g ÷ 196.97 g.mol⁻¹
Moles = 2.03 moles of Gold
Answer:
molarity of acid =0.0132 M
Explanation:
We are considering that the unknown acid is monoprotic. Let the acid is HA.
The reaction between NaOH and acid will be:
Thus one mole of acid will react with one mole of base.
The moles of base reacted = molarity of NaOH X volume of NaOH
The volume of NaOH used = Final burette reading - Initial reading
Volume of NaOH used = 22.50-0.55= 21.95 mL
Moles of NaOH = 0.1517X21.95=3.33 mmole
The moles of acid reacted = 3.33 mmole
The molarity of acid will be = 
Answer:
19.8m/s
Explanation:
Given parameters:
Mass of the ball = 10kg
Height of the rail = 20m
Unknown:
Velocity at the bottom of the rail = ?
Solution:
The velocity at the bottom of the rail is its final velocity.
Using the appropriate motion equation, we can find this parameter;
V² = U² + 2gH
V is the final velocity
U is the initial velocity
g is the acceleration due to gravity
H is the height
the ball was rolled from rest, U = 0
V² = O² + 2 x 9.8 x 20
V = 19.8m/s
