Answer:
The main advantage would be that with the pouring temperature being much higher, there is very little chance that the metal will solidify in the mould while busy pouring. This will allow for moulds that are quite intricate to still be fully filled. The drawbacks, though, include an increased chance defects forming which relates to shrinkage (cold shots, shrinkage pores, etc). Another drawback includes entrained air being present, due to the viscosity of the metal being low because of the high pouring temperature.
Answer:
The halogens are extremely reactive, whilst the noble gases are mainly inert.
Only some noble gases tend to form compounds, such as xenon and krypton. However, some like helium, almost have no compounds at all.
Noble gases also have octet rule shells, which causes the little reactivity associated with them.
To form bonds with noble gases, a lot of energy is required to form those bonds.
Halogens, on the other hand, are extremely reactive. Compounds like chlorine and fluorine must be stored carefully, as they will oxidise anything that they can find, just to get one extra electron to get an octet configuration.
Hope this helps :)
10 down: Particle with no charge
Answer: Neutron
