Answer:
When naming molecular compounds prefixes are used to dictate the number of a given element present in the compound. ” mono-” indicates one, “di-” indicates two, “tri-” is three, “tetra-” is four, “penta-” is five, and “hexa-” is six, “hepta-” is seven, “octo-” is eight, “nona-” is nine, and “deca” is ten.
Explanation:
BH3 VSEPR. Boron trihydride structure, BH3. On B, there are three bonded domains and no lone pairs, which give molecular geometries and trigonal planar electron-domain.
The wave-mechanical model of the atom is required to explain the spectra of elements with multi electron atoms.
<u>Explanation:</u>
Wave mechanical theory say that every electron surrounding a nucleus occupies a certain orbit and moves in a certain direction, but the orbit is like a wave of energy or cloud but not a ring. It was proposed in the 1920s, when scientists Erwin Schrodinger and Louis Victor de Broglie concluded that the Bohr’s model is not suitable for electron location determination.
Based on many assumptions, scientists began to guess as accurately as possible about the behaviour of electrons at different energy levels around the nucleus. Because all electrons are negatively charged, they tend to push their elbows when they are too close together, moving away and changing direction. Each plane has one or more orbits that have more than one electrons that move around the nucleus in a specific patterns or shape.
Answer:
2Cr³⁺(aq) + 3S²⁻(aq) ----> Cr₂S₃(s)
Explanation:
When aqueous solutions of chromium(III) chloride and ammonium sulfide are mixed together, chromium (III) chloride and ammonium sulfide undergoes a double displacement reaction to produce chromium (iii) sulphide as a precipitate and ammonium chloride which remains in solution.
The general equation of the reaction is given below:
2CrCl₃(aq) + 3(NH₄)₂S(aq) ----> Cr₂S₃(s) + 6NH₄Cl(aq)
The net equation of the reaction is given below:
2Cr³⁺(aq) + 3S²⁻(aq) ----> Cr₂S₃(s)
Answer: The mass of air present in the room is 37.068 kg
Explanation : Given,
Length of the room = 10.0 ft
Breadth of the room = 11.0 ft
Height of the room = 10.0 ft
To calculate the volume of the room by using the formula of volume of cuboid, we use the equation:

where,
V = volume of the room
l = length of the room
b = breadth of the room
h = height of of the room
Putting values in above equation, we get:

Conversion used : 
Now we have to calculate the mass of air in the room.



Conversion used : (1 kg = 1000 g)
Therefore, the mass of air present in the room is 37.068 kg