Answer:
10. D
9. A
8. A or B
Explanation:
10. Calcium has 20 electrons, but the Calcium ion has 18 electrons.
9. The mass of electrons are negligible.
8. Electrons have a very small mass where some consider it to have no mass.
Answer:
Four
Explanation:
AlCl₃(aq) ⟶ Al³⁺(aq) + 3Cl⁻(aq)
One mole of AlCl₃ produces 1 mol of Al³⁺ and 3 mol of Cl⁻.
That's four moles of ions.
They are odourless, colourless monatomic gases with full outer shells
Answer:
13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.
Explanation:
Length of the base = l
Width of the base = w
Height of the pyramid = h
Volume of the pyramid = 
We have:
Rate at which water is filled in cube = 
Square based pyramid:
l = 6 cm, w = 6 cm, h = 13 cm
Volume of the square based pyramid = V





Differentiating V with respect to dt:




Putting, h = 4 cm


13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.
Both are mainly composed of droplets of condensed water