Answer: Democritus atomic theory is the ancient theory that describes the nature of matter in terms of atoms whereas Dalton atomic theory is a modern scientific theory that describes the nature of matter in terms of atoms. According to Dalton's theory, atoms are identically same, but Democritus had no idea about it. Atoms are never created nor destroyed, they just rearrange.
Explanation:
Answer:
1. No 1 looks like a statement and not a question.
2.Ionic compounds are usually formed from the transfer of electrons from metals to Non metals. All others are Ionic compounds except HCl(Its a covalent compound).
3. The Formula would be K2S. Exchange of Radicals takes place. Sulphur has a -2 charge and potassium has a +1 charge. when they both exchange radicals... The compound is K2S.
4.Group 1 elements have only 1 electron in their outermost shell.
5. its charge will be +1 because it loses the 1 electron in its outermost shell.
6.Group 2 elements have 2electrons in their Valence shell.
7.Already answered. same as No 5.
8. Group 16;Also known as group 6. They have only 6 electrons in their outermost shell.
9.When they want to become stable... they acquire 2electrons to complete their octet... so they possess a -2 charge by forming an ion.
10. i)They form ions when Dissolve in solutions
ii) They are hard and brittle
iii) They have high boiling points
Answer:-
Oxygen gains electrons and is reduced.
Explanation:-
For this reaction the balanced chemical equation is
4Fe + 3O2 --> 2Fe2O3
When Oxygen is present as oxygen gas, the oxidation number of O is Zero since it is the only element present in Oxygen gas.
Similarly Iron is present in Fe with oxidation number Zero.
In the case of Fe2O3, Oxygen has the oxidation number -2 while Iron has +3.
So the oxidation number of Oxygen goes from Zero to -2.
Since the oxidation number decreases Oxygen is reduced.
Since reduction involves gain of electrons, Oxygen gains electrons.
The subatomic particle that gives off visible light is electrons
Answer:
D, Li2S
Explanation:
This is because Lithium, which is in group IA of the periodic table, has a charge of +1. Sulfur will have a charge of -2 because it is in group 6A in the periodic table, which means to balance these out, there needs to be 2 lithium ions which would result in a charge of +2. With Lithium now having a charge of +2 due to having two atoms in the compound, and sulfur already having a charge of -2 as one atom, these two cancel out meaning the compound is neutral.
