(also called Observational Error) is the difference between a measured quantity and its true value. It includes random error
Density equals mas divided by volume. You know the density and mass so use it to solve for the volume.
d= m/v
d= 19.3 g/mL
m= 50g
v=?
Plug it in. 19.3= 50/v
To solve for v you do the opposite of 50 divided by v which is 50 time v.
That cancels v from the right side of the equation. Do the same on the other side(times v)
19.3 * v=50
Now just divide both sides by 19.3 to get v alone.
Outgassing from active volcanoes
Answer: The coefficient we should change first is for
.
Explanation:
The given reaction equation is as follows.

Here, number of atoms present on reactant side are as follows.
- Al = 1
- Ni = 1
= 2
Number of atoms present on the product side are as follows.
- Al = 1
- Ni = 1
= 3
To balance this equation, multiply Al by 2 and
by 3 on reactant side. Also, multiply
by 2 and Ni by 3 on the product side.
Hence, the equation can be rewritten as follows.

Now, number of atoms present on reactant side are as follows.
- Al = 2
- Ni = 3
= 6
Number of atoms present on product side are as follows.
- Al = 2
- Ni = 3
= 6
Since, the atoms on both reactant and product side are same. Hence, it is now a balanced chemical equation.
Thus, we can conclude that the coefficient we should change first is for
.