Answer:
72
Explanation:
The pattern here may be hard to find at first, but it's this: the number in the middle of the triangle = (number at lower left corner of triangle x number at upper vertex of triangle) + (number at upper vertex of triangle x number at lower right corner of triangle).
Thus, for the missing value...
Missing value = (3x8) + (8x6) = 24+48 = 72.
Could you tell me what concept in chemistry relates to this? I'm interested.
Also check out stylesben's answer. Seems like there's several ways of doing this.
Okay to separate this mixture you will have to first use a magnet because the magnet will attract the iron filings out of the sand then you will remain with the sand and salt.
Next step is to add water to the sand and salt mixture the salt will dissolve in the water and the sand will not forming a heterogeneous mixture.Then using the method of filtration you can separate the sand from the salt solution leaving the salt solution
To separate the salt from the water use the method of evaporation this will enable you to get back the salt
In the end you should beable to have the sand,salt and iron filings separate.
Hope this was helpful to you.
Happy New Years !!! May your year be prosperous
1) It was Avogadro (option E).
The full name is Amadeo Avogadro. He was a famous Italian scientific. He formulated the Law that states that same volume of gases at same temperature and pressure corresponds same number of particles.
2) Cathode rays are electrons and have the largest charge mass / ratio of fundamental particles found in the atom (option E)
For example, electrons have the same charge magnitude than protons, but the mass of the electrons is a small fraction of the mass of the protons. (1/1840)
Answer:
Oxidizing element: Mg
Explanation:
Reaction of magnesium and oxygen can be written as:

while writting chemical reaction between two atom or element then write their natural form i.e. how that atom or element exist in the nature.
eg. reaction of any element with Oxygen atom then we can not write directly O because oxygen exist in the nature in form of 
finding oxidation number each side:
Reactant side:
Mg=0;
O=0;
product side:
Mg=+2;
O=-2;
from above:
oxidation number of Mg is increasing hence this is oxidizing element