<h2>
Answer:</h2>
Nucleus.
<h2>
Explanation:</h2>
- In an atom the nucleus has an overall positive charge as it contains the protons.
- Every atom has no overall charge (neutral). While atoms do contain charged particles, they have the same number of positive protons as negative electrons( for example a sodium atom has 11 electrons which are of negative charge and 11 protons which are of positive charge).
- These opposite charges cancel each other out making the atom neutral.
Result: Nucleus is the overall positive charge of an atom.
Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of
= 183.511 g/mole
- First we have to calculate the moles of Cu.

The moles of Cu = 4.7209 moles
From the given chemical formula,
we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of
= 4.4209 moles
- Now we have to calculate the mass of
.
Mass of
= Moles of
× Molar mass of
= 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of
= 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
The O Layer. I believe. Or the A horizon
Answer:
84 Joules are wasted per second.
Explanation:
An efficiency of 16% means 84% is wasted as heat energy.
Therefore;
For a 100W bulb;
Heat wasted = 84/100 × 100 W
= 84 W
Therefore;
84 W or 84 joules are wasted as heat per second