Answer:
1. an object that has been intentionally placed into orbit. they are called Artificial Satalites.Satanists.
2. a huge collection of gas ,dust and billions of stars and their solar systems held together by gravity.
3. a large object such as Jupiter or Earth that orbits a star. planets are smaller than stars and they do not produce light.
4. July 16, 1969
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
Sodium/Atomic number
11
Gold/Atomic number
79
Potassium/Atomic number
19
Silicon/Atomic number
14
Answer : Normally in any chemical reaction, if the enthalpy change i.e. ΔH is positive which means it is greater than zero then it can be called as an Endothermic Reaction.
Whereas, the system under study is absorbing heat that is produced during the reaction. So if ΔH is found to be positive then it can be called as endothermic reaction.
