Answer:
From Top to Bottom:
- Democritus coming up with the concept of an atom
- Dalton discovering that atoms are the smallest part of an element
- Rutherford discovering the nucleus of an atom
- Thomson discovering electrons
- Bohr modeling electrons orbiting the nucleus
- Schrodinger modeling electrons in the electron cloud
Explanation:
The best way to think about this is from the inside out. Democrats (who lived long before any of the other scientists mentioned) was the one who thought of the idea of the atom. - Therefore, this must be first because all other choices are elaborations on the idea that atoms exist. Next must be Dalton. Dalton saw atoms as "cannonballs" if you will; a solid mass. So then after that, Rutherford and his gold foil experiment (he discovered that some rays he shot through gold foil were deflected back; ie the existence of concentrated areas in an atom, ie the nucleus). Then we get into the information on electrons. We must start with discovery (Thomson). Heres where it gets complicated. Electrons don't <em>actually </em>orbit the nucleus, they exist in electron clouds. So it would be Bohr, who came up with the idea that electron exist outside the nucleus, then Schrodinger, who elaborated on Bohr's theory. Hope this helps!
Nat, Junior
Accel + AP Chem student
When we describe the energy of a particle as quantized, we mean that only certain values of energy are allowed. ... In this case, whenever we measure the particle's energy, we will find one of those values. If the particle is measured to have 4 Joules of energy, we also know how much energy the particle can gain or lose. Quantized energy means that the electrons can possess only certain discrete energy values; values between those quantized values are not permitted
Answer:
4) transferred from the valence shell of one atom to the valence shell of another atom
Explanation:
Electrons are located outside of the nucleus which contains the protons and the neutrons.
For bonds to form, valence electrons located in the outermost shell electrons are involved. These are the valence electrons. These outer shell electrons can be shared or transferred between two combining atoms to form stable atoms.
In ionic bonds, the electrons are transferred from one specie to another. The atom that loses the electrons becomes positively charged and the receiving atom becomes negatively charged. This is the crux of ionic bonds.
Air is a mixture, Its constituens can be seperated
When the charged balloon is brought near the wall, it repels some of the negatively charged electrons in that part of the wall. Therefore, that part of the wall is left repelled.
<u>Explanation</u>:
- Balloons don't stick to walls. However, if you rub the balloon on an appropriate piece of material such as clothing or a wall, electrons are pulled from the other material to the balloon.
- The balloon now as more electrons than normal and therefore has an overall negative charge. Two balloons like this will repel each other.
- The other material now has an overall positive charge. Because opposite charges attract, the balloon will now appear to stick to the other material. If you didn't rub the balloon first, it's charge would be neutral and it wouldn't stick to the wall.
