Answer:
NaI
Explanation:
In I₂, HI and IBr, both atoms are nonmetals and they form covalent bonds in which electrons are shared.
In NaI, Na is a metal and I a nonmetal, so they form an ionic bond, where Na loses an electron to form Na⁺ and I gains an electron to form I⁻. Anions and cations are attracted to each other through electrostatic forces.
Since ionic bonds are stronger than covalent bonds, more energy is required to break them in the melting process, thus having higher melting points.
All in all, NaI is the one with the highest melting point.
Answer:
Advantages :they are used for seeing chemical reactions .
they are used for doing chemical experiment .
they are used for making affective medicines .
Disadvantages :they harms to our environment.
they can make side effects in our body by affective medicines made by chemicals.
while doing different unknown experiments they make explosions which can also harm to us.
First a balanced reaction equation must be established:

→

Now if mass of aluminum = 145 g
the moles of aluminum = (MASS) ÷ (MOLAR MASS) = 145 g ÷ 30 g/mol
= 4.83 mols
Now the mole ratio of Al : O₂ based on the equation is 4 : 3
[
4Al +
3 O₂ → 2 Al₂O₃]
∴ if moles of Al = 4.83 moles
then moles of O₂ = (4.83 mol ÷ 4) × 3
=
3.63 mol (to 2 sig. fig.)
Thus it can be concluded that
3.63 moles of oxygen is needed to react completely with 145 g of aluminum.
If the ending substance has changed its properties. For example if iron rusts it is a chemical change because it is no longer the same as before it is now just rust. A physical change only changes the appearance but burning something or changing it's chemical properties is a chemical change.