Question

How many protons are in one kg of lead? b) How many electrons are in one kg of lead? c) What is the total negative charge of these electrons in Coulombs?

Answer 1

Answer:

Number of protons = $2.3836\times 10^{26}$

Number of electrons = $2.3836\times 10^{26}$

Charge on these electrons = -$3.8185\times 10^{7}\ C$

Explanation:

1 atom of lead contains 82 protons and 82 electrons

1 mole = $6.023\times 10^{23}$ atoms

Thus,

1 mole of lead contains $82\times 6.023\times 10^{23}$ protons

Also, 1 mole of lead weighs 207.2 g

So,

207.2 g of lead contains $82\times 6.023\times 10^{23}$ protons

1 kg = 1000 g

So,

1000 g or 1 kg of lead contains $\frac {82\times 6.023\times 10^{23}}{207.2}\times 1000$ protons

Number of protons = $2.3836\times 10^{26}$

Also, for neutral atom, number of protons = number of electrons.

Thus,

Number of electrons = $2.3836\times 10^{26}$

Also,

Charge of 1 electron = - $1.602\times 10^{-19}\ C$

Charge on these electrons = -$2.3836\times 10^{26}\times 1.602\times 10^{-19}\ C$

Charge on these electrons = -$3.8185\times 10^{7}\ C$