+2, because the element has more protons than electrons now
False
only observing chemical property will change its identity
Hello @Lucysrv18,
How are you doing? In this case, we know that Electromagnetic waves that are visible to the human eye is neither made up of two electromagnetic waves nor three. Therefore B and C is incorrect.
These electromagnetic waves are divided and they are our final two options. For sure, i can say that the wavelengths in a visible electromagnetic wave are not divided into nine, but instead it is divided into 7.
The answer to your question is A.
Thank you,
Darian D.
To obey the Law of Conservation of Mass, the sum of all individual elements of a compound is equal to the mass of the compound. So, if HCN has a mass of 7.83 grams, then
7.83 g = mass of H + mass of C + mass of N
We know the masses of H and N to be 0.290 g and 4.06 g, respectively. Hence, we can find for the mass of C:
7.83 = 0.29 + mass of C + 4.06
mass of C = 3.48 g
As an extension to the Law of Conservation of Mass, there is also a Law of Definite Proportions. According to Dalton's atomic theory, a compound is formed from a fixed ratio of its individual elements. From our previous calculations, we know that the mass ratio of H to C to N is 0.29 g: 3.48 g:4.06 grams. The ratio could also be expressed in percentages. Let's find the mass percentage of Carbon in HCN to be used later:
mass % of Carbon = (3.48 g/7.83 g)*100
mass % of Carbon = 44.44%
So, if you collect a different mass of HCN, say 3.37 g, the corresponding mass of Carbon is equal to:
Mass of Carbon = (3.37)(44.44%)
Mass of Carbon = 1.498 g
