How many times does the electron go round the firstBohr orbit of hydrogen atoms in 1 s?

To answer this question, we need to know the speed of an electron in the first Bohr orbit of a hydrogen atom and the circumference of the first Bohr orbit.

1. The speed of an electron in the first Bohr orbit of a hydrogen atom is approximately 2.18 x 10^6 m/s.

2. The radius of the first Bohr orbit (also known as the Bohr radius) is approximately 5.29 x 10^-11 m. Therefore, the circumference of the first Bohr orbit is 2πr = 2π(5.29 x 10^-11 m) = 3.32 x 10^-10 m.

3. To find out how many times the electron goes around the first Bohr orbit in 1 second, we divide the electron's speed by the circumference of the orbit.

So, (2.18 x 10^6 m/s) / (3.32 x 10^-10 m) = approximately 6.57 x 10^15 times.

Therefore, the electron goes around the first Bohr orbit of a hydrogen atom approximately 6.57 x 10^15 times in 1 second.