1. Using the following equation: Fe2O3 + 3 H2 > 2 Fe + 3 H2O

Calculate how many grams of iron can be made from 16.5 grams of Fe2O3 by the following equation.
2.Using the following equation:

4 NH3 + 5 O2 > 4 NO + 6 H2O

How many grams of oxygen (O2) are needed to react with 56.8 grams of ammonia by this reaction?
3. Using the following equation:

Sn + 2HF > SnF2 + H2

a) How many grams of SnF2 are produced from the reaction of 30.0 g of HF?
b) How many moles of HF will be needed to react with 48 grams of Tin, (Sn)?

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante

they all get energy from eating other animals, dead animals to be more precise.

hienas tends to steal pray from other animals. crows and vultures tend to eat dead animals and leftovers.

hope it ,

bioteacher101