One gram of platinum has 3.09 × 1021 atoms, and each platinum atom has 78 electrons.

How many electrons are contained in 4.00 g of platinum? The elemental charge is 1.6 × 10−19 C.
Answer in units of electrons

1.92816E24

To find the number of electrons contained in 4.00 g of platinum, we can follow these steps:

1. Determine the number of platinum atoms in 4.00 g of platinum:
- Given: 1 gram of platinum has 3.09 × 10^21 atoms
- Convert the given mass of platinum to grams: 4.00 g
- Use the given conversion factor: 1 gram of platinum = 3.09 × 10^21 atoms
- Calculate: 4.00 g * (3.09 × 10^21 atoms / 1 gram) = 1.236 × 10^22 atoms

2. Calculate the number of electrons contained in the given number of platinum atoms:
- Given: Each platinum atom has 78 electrons
- Multiply the number of platinum atoms by the number of electrons per platinum atom: 1.236 × 10^22 atoms * 78 electrons = 9.6288 × 10^23 electrons

Therefore, there are approximately 9.6288 × 10^23 electrons contained in 4.00 g of platinum.