Answer: 1) 500, 000
2) Five hundred thousand
3) 
Step-by-step explanation:
To express: 5 of 100, 000 in three expressions (First - number. second - word , third - scientific )
5 of 100, 000 = 5 x 100, 000 = <u>500, 000</u>
In word -<u> Five hundred thousand</u> [ as place value of 5 = hundred thousand]
In scientific notation, 
Hence, the required expressions:
1) 500, 000
2) Five hundred thousand
3) 