Atomic structure

What is called the smallest unit of an element.

• Matter

• Nucleus

• Atom

• Proton

Atoms are made up of how many subatomic particles ?

• One

• Two

• Three

• Four

Are neutrons negatively charged?

• Yes

• No

The number of protons in a nucleus of an atom is called ?

• Atom number

• Atomic number

• Proton number

• Positive number

During ionization, atom which gains an electron is a negative ion.

• True

• False

Mass of one electron :

• 0.000005499 kg

• 0.000549 g

• 0.000549 au

• 0.000549 amu

ISOTOPES of an element are atoms that have the different atomic number (Z) as the other atoms of the element, but a different mass number (A).

• True

• False

ISOTOPES of an element are atoms that have the same atomic number (Z) as the other atoms of the element, but a different mass number (A).

• True

• False

Choose the best option relevant to the statements given below :

The ATOMIC NUMBER (Z) of any atom is the number of protons in its nucleus.

The MASS NUMBER (A) of an atom is the number of protons and the number of neutrons in its nucleus.

• A = Z + N, and N = A +Z

• A = Z - N, and N = A – Z

• A = Z + N, and N = A – Z

• None of the above

In 1926, Quantum model was proposed by ?

• Niels Bohr

• J.J Thomson

• John Dalton

• Ernest Rutherford

• Erwin Schrodinger