A physical change.
Physical change = can be reverted + doesn't change substance
Chemical = changes substance
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:
Its kinetic energy.
Explanation:
In a liquid, the molecules are so close together that there is very little empty space. A liquid also has a definite volume, because molecules in a liquid do not break away from the attractive forces. The molecules can, however, move past one another freely, and so a liquid can flow, can be poured, and assumes the shape of its container.
An increase in the temperature of a liquid causes an increase in the average speed of its molecules. As the temperature of a liquid increases, the molecules move faster thereby increasing the liquid's kinetic energy.
The amino acids are the molecules where we can found the carboxyl group (-
), amino group (-
), hydrogen atom (H) and a residual R-group. On the structure of the residual R-group the name of the amino acid depends. Like if R is hydrogen (H) the amino acid is alanine; If R- group is a phenyl group i.e. 
, the compound is called phenyl alanine. The structure of the general amino acid skeleton can be shown as-
