Nucleus

A Balmer series spectrum is formed when electrons from excited state fall down to ground state of n= ___.

Q5. Which of the following statement is incorrect?

• X-rays spectrum of all wavelengths starting from a minimum wavelength,is called continuous spectrum

• X-ray lines corresponding to certain wavelength are called characteristic spectrum

• Continuous X-ray spectrum depends on the type of target material

• Characteristic X-ray spectrum depends on potential applied

• all the above

The mass number of a nucleus is equal to

• the number of neutrons in the nucleus

• the number of protons in the nucleus

• the number of nucleons in the nucleus

• none of them

which atom has  4 neutrons?

• Li-6
• Li-7
• Li-8
• they have the same # of neutrons

An atom has a mass number of 23 and atomic number 11. The number of protons is _________.

• 11

• 12

• 23

• 44

Atoms can be broken in to smaller components.

• True

• False

The mass of one proton is greater than the mass of one...

• neutron
• electron

What are the 3 subatomic particles that make-up the atom?

• protons, neutrons, and isotopes
• neutrons, isotopes, and electrons
• positives, negatives, and electrons
• protons, neutrons, and electrons

How many atoms are in this molecule?

• 1

• 2

• 3

• 4

How many protons does an O₂ atom have?

• 8
• 24
• 16
• When is lunch?