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

Number of protons =
`2.3836* 10^(26)`

Number of electrons =
`2.3836* 10^(26)`

Charge on these electrons = -
`3.8185* 10^(7)\ C`

Step-by-step explanation:

1 atom of lead contains 82 protons and 82 electrons

1 mole =
`6.023* 10^(23)` atoms

Thus,

1 mole of lead contains
`82* 6.023* 10^(23)` protons

Also, 1 mole of lead weighs 207.2 g

So,

207.2 g of lead contains
`82* 6.023* 10^(23)` protons

1 kg = 1000 g

So,

1000 g or 1 kg of lead contains
`\frac {82* 6.023* 10^(23)}{207.2}* 1000` protons

Number of protons =
`2.3836* 10^(26)`

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

Thus,

Number of electrons =
`2.3836* 10^(26)`

Also,

Charge of 1 electron = -
`1.602* 10^(-19)\ C`

Charge on these electrons = -
`2.3836* 10^(26)* 1.602* 10^(-19)\ C`

Charge on these electrons = -
`3.8185* 10^(7)\ C`