Which particles can be stopped by human skin? ) alpha and beta particles only alpha particles alpha and gamma particles beta and gamma particles

Answer : The correct option is, only alpha particles.

Explanation :

Penetration power : It is defined as the movement of the rays or the particles through the object.  As more the energy of a particle, the more will be the penetrating power.

The ascending or increasing order of the penetration power of the particles will be :

Alpha rays < Beta rays < Gamma rays

The penetrating power of the particles alpha, beta and gamma rays varies differently.

Hence, the particles can be stopped by human skin is only alpha particles.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

the cold front replaces the warmer air at the ground level changing the wind to be breezy and denser.there is also an immediate drop in the temperature.