Answer : The amount of energy evolved during the reaction is,
.
Solution : Given,

Mass of Al = 51.2 g
Molar mass of Al = 27 g/mole
First we have to calculate the moles of Al.
The balanced combustion reaction is,

From the given reaction, we conclude that
As, 2 moles of Al evolved energy = 
So, 1.896 moles of Al evolved energy = 
Therefore, the amount of energy evolved during the reaction is,
.
Answer:
Training officers in how to properly collect evidence
Explanation:
Forensic science is an interesting branch of science that involves the use of scientific procedures to solve a crime case. It encompasses collection of physical evidence from the crime scene and analyzing it in a laboratory using scientific means.
A forensic scientist is the individual in charge of performing these scientific procedures. His/her major role is to run the scientific analysis of the physical evidence brought in by the officers, however, he/she can also perform the task of training officers in how to properly collect evidence, in order not to damage the evidence or render it invalid for use.
Atomic mass gold ( Au) = 196.96 a.m.u
196.96 g ------------ 6.02x10²³ atoms
2.35 g -------------- ??
2.35 x (6.02x10²³) / 196.96
=> 7.18x10²¹ atoms
Dipole-dipole forces are probably the simplest to understand. You probably already know that in an ionic solid like NaCl, the solid is held together by Coulomb attractions between the oppositely-charges ions. The Na+ and Cl- ions alternate so the Coulomb forces are attractive