The substance would be referred to as a compound substance.
Answer: Energy of reactants = 30, Energy of products = 10
Exothermic
Activation energy for forward reaction is 10.
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and 
for the reaction comes out to be negative.
Energy of reactants = 30
Energy of products = 10
Thus as energy of the product < energy of the reactant, the reaction is exothermic.
Activation energy 
is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
for forward reaction is (40-30) = 10.
Hey there!
To find the density of an object, you must use this formula:
Density=Mass/Volume
Knowing that your mass is 128.3741, the only information you need left would be to find the volume of the cube.
Because the side length of the cube is given, you can multiply the length three times in order to find its volume:
1.25*1.25*1.25
=1.953125
Now that you have your volume and mass, divide the mass by the volume to find the density:
128.3741/1.953125
=65.7275392
Therefore, your density would be 65.7275392 grams per inches cubed.
Isotope ¹⁸F⁻ contains:
1) p⁺ = 9; number of protons.
Fluorine has a<span>tomic number Z = 9 (total number of protons).
2) e</span>⁻<span> = 10; </span>number of electrons.<span>
In element number of electrons and protons are the same, because element has neutral charge, but because in this example, fluorine is anion with negative charge, it has one electron more.
3) n</span>° = 9; number of neutrons.
<span>Mass number
A = 18 is total number of protons and neutrons in a nucleus, so number of neutrons is A-Z = 18-9=9.</span>
Balanced equation
Mg₃(PO₄)₂ + 2Al(NO₃)₃ → 3Mg(NO₃)₂ + 2AlPO₄
<h3>Further explanation</h3>
Given
Reaction
Mg3(PO4)2 + Al(NO3)3 → Mg(NO3)2 + AlPO4
Required
Balanced equation
Solution
Give a coefficient :
Mg₃(PO₄)₂ + aAl(NO₃)₃ → bMg(NO₃)₂ + cAlPO₄
Make an equation :
Mg, left = 3, right=b⇒b=3
P, left=2, right=c⇒c=2
Al, left=a, right=c⇒a=c⇒a=2
The reaction becomes :
Mg₃(PO₄)₂ + 2Al(NO₃)₃ → 3Mg(NO₃)₂ + 2AlPO₄
