Answer:
<h2>Which of the following statements correctly describes a difference between mechanical waves and electromagnetic waves?</h2><h2><em>
:- Mechanical waves require a medium to travel through, whereas electromagnetic waves can travel through empty space.</em></h2>
<em>is the correct</em>
<em>pls mark me as brainliest pls </em>
<em></em>
<h3 />
Answer:
Atom is the building block of matter. The atom itself made up of subatomic particles electron, proton and neutron.
Explanation:
Long time ago, Greek philosopher thoughts that matter can be divided into smaller particles until a point is reached when the basic unit is obtained which can not be further sub divided. A Greek philosopher Democritus called these basic units "Atom".
Later on modern research showed that atom could be divided into smaller particles electron, proton and neutron. These smaller particles are called sub-atomic particles of atom.
Atoms are the fundamental unit of matter. Every thing in the universe that occupy space and have mass is called matter. we can say that every matter is composed of atoms. while the atom is composed of subatomic particles called electron proton and neutron.
Electron:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol = e-
Mass= 9.10938356×10-31 Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
Proton and Neutron:
An atom consist of positively charged central core (nucleus) that is made up of Proton and neutron. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P+
Symbol of neutron= n0
Mass of proton=1.672623×10-27 Kg
Mass of neutron=1.674929×10-27 Kg
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons.
Answer:
The mass of CO22 in total is 264 g.
The atomic mass for C is 12 g / mole.
The molar mass for CO22 is (12 + (2 × 16)) = 44 g / mole.
m C = (12 / 44) × 264 = 72 g
So, there are 72 g of C in 264 g of CO2
Explanation:
there's the answer have a good day.
Answer:
I don't know if you can directly prove it with evidence if you haven't observed it but you can maybe take an educated guess by the aftermath of it?
For example, you see a burnt log. At this time, people don't know what fire is. After we study the log, we could see that it takes extreme temperature in order to burn the log and that would help people see that there is a force like fire that can cause this. In a way, finding out that extreme temperatures burns stuff is another step closer to the discovery and proof of fire
I hope that makes sense
