Are These Numbers in Standard Form?

Question 1:

4.62× 10 5
Yes

Question 2:

8.26× 10 6
Yes

Question 3:

8.17× 10 6
Yes

Question 4:

5.1× 10 -4
Yes

Question 5:

6.05× 10 5
Yes

Question 6:

7.68× 10 3
Yes