Answer: With atomic number 20, calcium atoms have 20 positive protons, and the ion has only 18 electrons, which means the net charge is +2. Calcium ions are essential for muscle contractions, nerve impulses, and bone maintenance.
:
Density(D) is defined as Mass(M) divided by Volume(V).
The formula for Density is:
D = M / V.
Another way to remember the formula for Density is to remember "Mass per unit of volume".
I hope this helps!
Answer:
MSDS -- Material Safety Data sheet
Explanation:
The full form of MSDS is Material Safety Data sheet. A Material Safety Data Sheet is a document which contains the information related to the potential hazards (fire or reactivity and environmental and health ) and includes how to work or use the chemical product safely.
It is regarded as an essential starting point for development of the complete health as well as safety program. MSDS also contains other information such as the use of the chemical, its storage and also handling and the emergency procedures that are related to the hazards of the material.
First let's find out the oxidation number of Fe in K₄[Fe(CN)₆] compound.
The oxidation number of cation, K is +1. Hence, the total charge of the anion, [Fe(CN)₆] is -4. CN has charge has -1. There are 6 CN in anion. Let's assume the oxidation number of Fe is 'a'.
Sum of the oxidation numbers of each element = Charge of the compound
a + 6 x (-1) = -4
a -6 = -4
a = +2
Hence, oxidation number of Fe in [Fe(CN)₆]⁴⁻ is +2.
Now Fe has the atomic number as 26. Hence, number of electrons in Fe at ground state is 26.
Electron configuration = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s² = [Ar] 3d⁶ 4s²
When making Fe²⁺, Fe releases 2 electrons. Hence, the number of electrons in Fe²⁺ is 26 - 2 = 24.
Hence, the electron configuration of Fe²⁺ = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶
= [Ar] 3d⁶
Hence, the number of 3d electrons of Fe in K₄[Fe(CN)₆] compound is 6.
The atomic number is the numbers of protons
