Answer:
The sum of positive and negative charges in a unit of Al2O3 equals zero.
Aluminium has a charge of +3 while Oxygen has a charge of -2 on each ion.
Al203 has 2 Al atoms and 3 O atoms.
Charge on Al2O3 = 2(charge on Al ion) + 3(charge on O ion)
= 2(3) + 3(-2)
= 6 - 6
= 0
Explanation:
Aluminium has 3 electrons in the outermost shell and has the tendency to lose those 3 electrons to form a positive ion and have a complete outermost shell.
Whereas, Oxygen has 6 electrons in the outermost and has the tendency to accept two more electrons to form a negative ion and have a complete outermost shell.
Atoms of the same element having equal numbers of protons, but different numbers of neutrons is called isotope.
Answer:


Explanation:
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²
= Mass of sphere = 2000 kg
= Mass of other sphere = 2.1 kg
r = Distance between spheres
Force of gravity is given by

The gravitational force is 

The gravitational force is 
PART A)
Here we know that
potential difference across the wire is

resistance of wire is

now by ohm's law



Part b)
Power rating is defined as rate of electrical energy
it is defined as

now we have

