<span>Answer: B) sound waves</span>
<span> There are 2 classifications of waves according to the media of propagation.</span>
<span> <span>Mechanical Waves – needs a medium, an example is sound waves. Sound waves do not travel through a vacuum. Sound waves move by replacing one particle with another. Particles vibrate and that is why we hear the sounds.</span> <span>Electromagnetic Waves and electrostatic waves are one but the same. They do<span> not require a medium. – an example is light waves.</span></span> </span>
Answer:
The sum of the protons and neutrons
Explanation:
mass number= proton number + neutron number
Dmitri Mendeleev was the creator and therefore organizer of the periodic table.
Bohr atomic model different from the plum-pudding model as the Plum pudding model did not encounter the concept of nucleus it simply says compares atom with a pudding in which electrons are spread around as rasins in a pudding while bohr explain atom that is having nucleus that serves as a centre of the atom , and there are electrons around nucleus that occupy certain energy levels.