Answer:
Both are equal
Explanation:
Mass of starting material i.e Aluminium is 
grams
The weight of oxygen is 
There are 4 atoms of aluminium and 3 atoms of oxygen
Thus, the total mass of starting material is
mass of one atom of aluminium 
mass of one atom of oxygen
grams
Mass of new substance is also equal to
mass of one atom of aluminium mass of one atom of oxygen
grams
In most cases, carbon shares electrons with other atoms (usual valence of 4). This is because carbon typically bonds with elements which have a similar electronegativity. Examples of covalent bonds formed by carbon include carbon-carbon, carbon-hydrogen, and carbon-oxygen bonds
We will use the expression for freezing point depression ∆Tf
∆Tf = i Kf m
Since we know that the freezing point of water is 0 degree Celsius, temperature change ∆Tf is
∆Tf = 0C - (-3°C) = 3°C
and the van't Hoff Factor i is approximately equal to 2 since one molecule of KCl in aqueous solution will produce one K+ ion and one Cl- ion:
KCl → K+ + Cl-
Therefore, the molality m of the solution can be calculated as
3 = 2 * 1.86 * m
m = 3 / (2 * 1.86)
m = 0.80 molal
The correct answer is:
B; A new substance forms.
Explanation:
A physical change, such as a state change or dissolving, does not produce a new substance, but an abundant change does. In a chemical reaction, the atoms and molecules that connect with each other are described as reactants. Chemical reactions happen when chemical bonds are broken and formed. If the molecules in a substance crash into each other with enough energy, some of the bonds in the molecules can break. The atoms can make new bonds with different atoms. A new substance forms.
