To know the number of atoms, it will be necessary to use the formula of avogadro. We calculate the number of moles then we can calculate the number of avogadro.
The molar mass of:
Phosphorus = 31g / mol
Mercury = 200 g / mol
Bismuth = 209 g / mol
Strontium = 87 g / mol.
The number of avogadro (N) is 6.023 10 ^ 23
n = m (mass) / M (molar mass)
number of atoms = n. N = m / M . N
number of phosphorus atoms = 5.14/31 . 6.023 10^23 = 9.98 10 ^ 22 atoms
Number of atoms of mercury = 2.16/200 . 6.023 10^23 = 6.5 10 ^ 21 atoms
Number of bismuth atoms = 1.8/209 . 6.023 10^23 = 5.18 10 ^ 21 atoms
Number of strontium atoms = 8.8 x 10-2 /87 . 6.023 10^23 = 6.09 10 ^ 20 atoms
Answer:
0.66g/mL
Explanation:
La densidad es una propiedad de la materia definida como la masa de una sustancia en un determinado volumen.
En este problema, podemos hallar la densidad sabiendo que la diferencia de masas del pic vacío y el pic lleno es la masa de la solución y que el volumen que ocupa es de 25mL:
<em>Masa solución:</em>
25g - 8.5g = 16.5g
Así, la densidad será:
16.5g / 25mL =
<h3>0.66g/mL</h3>
Answer:
A and B
Explanation:
This is because there was emission of gamma (Y) radiations in both the reactions.
Answer:
c. ₆¹²C and ₆¹³C
Explanation:
Properly writing the given options:
a. ₁¹H and ₁¹H⁺
b. ₇¹⁴N and ₇¹⁴N³⁻
c. ₆¹²C and ₆¹³C
Electrons are the crux of chemical reactions. These negatively charged subatomic particles determines chemical properties of atoms and how they combine with other atoms.
Atoms having the same number of electrons especially in their valence shells shares similar chemical properties.
From the problem above, we have been given some information about the atom.
The mass number is given by the superscript before the symbol of the atom and it signifies the sum of the number of protons and neutrons in the atom.
The atomic number is shown by the subscript and it denotes the number of protons in the atom.
For neutral atoms that has not lost or gained any additional electron, the atomic number is the same as the number of electrons.
The superscript after the atom is the charge on the particle. It represents the number of electrons lost or gained by the atom.
In {c. ₆¹²C and ₆¹³C}, the atom is in a neutral state. Here the atomic number which is 6 is the number of protons in the atom. This is also the number of electrons in the atom. Therefore, the two atoms would have similar chemical properties and behavior.
This is not so for the others as their number electrons are different.