Answer:
.
Explanation:
Based on the electron configuration of this ion, count the number of electrons in this ion in total:
.
Each electron has a charge of .
Atoms are neutral and have charge. However, when an atom gains one extra electron, it becomes an ion with a charge of . Likewise, when that ion gains another electron, the charge on this ion would become .
The ion in this question has a charge of . In other words, this ion is formed after its corresponding atom gains two extra electrons. This ion has electrons in total. Therefore, the atom would have initially contained electrons. The atomic number of this atom would be .
Refer to a modern copy of the periodic table. The element with an atomic number of is sulphur with atomic symbol . To denote the ion, place the charge written backwards ("" for a charge of ) as the superscript of the atomic symbol:
.
Atoms of the same element, containing the same number of protons, but different numbers of neutrons, are known as isotopes. Isotopes of any given element all contain the same number of protons, so they have the same atomic number (for example, the atomic number of helium is always 2).
Answer:
CH₂
Explanation:
From the question given above, the following data were obtained:
Mass of compound = 1 g
Mass of CO₂ = 3.14 g
Mass of H₂O = 1.29 g
Empirical formula =?
Next, we shall determine the mass of Carbon and hydrogen present in the compound. This can be obtained as follow:
For Carbon, C:
Mass of CO₂ = 3.14 g
Molar mass of CO₂ = 12 + (2×16)
= 12 + 32
= 44 g/mol
Molar mass of C = 12 g/mol
Mass of C =?
Mass of C = molar mass of C/ Molar mass of CO₂ × Mass of CO₂
Mass of C = 12/44 × 3.14
Mass of C = 0.86 g
For hydrogen, H:
Mass of C = 0.86 g
Mass of compound = 1 g
Mass of H =?
Mass of H = (Mass of compound) – (mass of C)
Mass of H = 1 – 0.86
Mass of H = 0.14 g
Finally, we shall determine the empirical formula of the cyclopropane. This can be obtained as follow:
Mass of C = 0.86 g
Mass of H = 0.14 g
Divide by their molar mass
C = 0.86 / 12 = 0.07
H = 0.14 / 1 = 0.14
Divide by the smallest
C = 0.07 / 0.07 = 1
H = 0.14 / 0.07 = 2
Thus, the empirical formula of cyclopropane is CH₂
Answer:C
Explanation: Because the oldest fossils are in deeper layers
Answer:
The de-exitation of electron to its lower energy level cause the emission spectrum of an element.
Explanation:
The electron is jumped into higher level and back into lower level by absorbing and releasing the energy.
The process is called excitation and de-excitation.
Excitation:
When the energy is provided to the atom the electrons by absorbing the energy jump to the higher energy levels. This process is called excitation. The amount of energy absorbed by the electron is exactly equal to the energy difference of orbits. For example if electron jumped from K to L it must absorbed the energy which is equal the energy difference of these two level. The excited electron thus move back to lower energy level which is K by releasing the energy because electron can not stay longer in higher energy level and comes to ground state.
De-excitation:
When the excited electron fall back to the lower energy levels the energy is released in the form of radiations. This energy is exactly equal to the energy difference between the orbits. These radiations gives the emission spectrum of that element. The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum
.