# Fundamental Particles of Atom Worksheet

Fundamental particles of atom

Atom is a small unit of matter which consists of a dense nucleus surrounded by a negatively charged electrons. Atomic nucleus contains a mix of protons and neutrons. Protons are positively charged whereas, neutrons are electrically neutral.

Some of the important questions and answers related to fundamental particles of atom are listed below.

Worksheet Questions:

1. Which is not correct about electrons?

(a)    Discovered by Chedwick

(b)   Named by J.L. Stoney

(c)    Present inside the nucleus

(d)   It has maximum e / m ratio

2. Neutron was discovered late mainly because:

(a)    It is unstable

(b)   It is neutral or chargeless

(c)    It is heavier

(d)   All of these

3. Which atom does not have any neutron?

(a)    H-atom

(b)   He-atom

(c)    Li-atom

(d)   None of these

4. The ratio of e / m of p and $\alpha$ is:

(a)    1 : 2

(b)   2 : 1

(c)    1 : 3

(d)   1 : 1

5. Which is not correctly matched:

(a)    Particle nature of $e^-$ is given by $\to$ Bohr

(b)   The heaviest sub-atomic particle $\to$neutron among $e, p, n. e^+$

(c)    Electron is $\to$non fundamental particle

(d)   Outside the nucleus $\to$ neutron is unstable

6. Which is incorrect statement here?

(a)     $e^-$ has unit –ve charge

(b)   $e^+$ is called anti electron

(c)    $e^-$is also written as $\beta^-$

(d)   M have +ve value of e / m