The sub-atomic particles of an atom are the proton, electron and the neutron. An electron has a charge of -1 and a smaller
mass than a proton. Proton has the same mass with the neutron. The ratio
between the mass of a proton and an electron is about 2000. An electron has an
equal value but negative charge with the proton.
Answer: Beta particles cannot penetrate very far into solids because they <span><u>have no mass.
</u>
Reason<u>:
</u>Penetrating power of particle depending upon the velocity and mass of particle. Greater the mass and velocity. Higher will be the penetrating power. In case of Beta particles, they are electrons. Mass of an electron is 9.1 X </span>

Kg. Due to such negligible mass, they have very low penetrating power. <span /><span><u>
</u></span>
Answer:
Here just look at the pic here
Explanation:
A penny for the scratch test (low hardness)a hand lens for inspection a peice of tile for a streak test a geologic hammer to test for cleavage of fracture and the pocket knife for the scratch test (high hardness)