Answer:
D. Its temperature will remain 100 C until all the vapours condenses
Explanation:
Heat absorbed by a substance to change the state of matter is known as latent heat. This heat is utilized to break the bonds between atoms of the substance so that they can undergo phase change.
So, when water boils at 100 degree Celsius then temperature will remain constant unless and until all the water changes into vapor. As it is the latent heat that breaks the bonds between hydrogen and oxygen atoms of water so that liquid state can change into gaseous state.
Since latent heat is a hidden heat, that is why, it does not get reflected and there is no change in temperature due to it.
Thus, we can conclude that it is true that temperature will remain at 100°C until all the vapor condenses for a sample of water vapor at 101°C as it cools.
A and d is physical, b and c is chemical
Explanation:
12)
a) Sodium + oxygen = ?
When sodium reacts oxygen its forms sodium oxide as a product.

b) magnesium + fluorine = ?
When magnesium reacts with fluorine its forms magnesium fluoride as a product.

13)
a) 
Decomposition of mercury(II) oxide on heating gives out mercury and oxygen gas.
b)
The electrolytic decomposition of water gives out hydrogen gas amd oxygen gas.
1. If you find shielding that blocks gamma radiation,then it will most likely also block the other two types. (as the hardest radiation)
2. When nuclear radiation enters the tube of a Geiger counter, it the excited atoms of the gas contained in the tube. (this type <span>deposits all energy into a single atom)</span>
3 The particles that make up protons and neutrons and are thought to be basic units of matter are <span>quarks.</span>
The correct answer is option 4 and 5.
The electron domain geometry for an ammonia molecule, NH₃ has tetrahedral electron domain geometry. In NH₃ there are three bond pair electrons and one lone pair electron. Therefore, NH₃ has four electron pairs which are distributed in a tetrahedral shape.
The molecular geometry for an ammonia molecule, NH₃ is trigonal-pyramidal molecular geometry. Ammonia has one lone pair of electron and three bond pairs of electrons thus the resulting molecular geometry is trigonal-pyramidal.