<u>Answer 2 :</u> The given electronic configuration for a neutral atom of phosphorous in its ground state is incorrect.
Explanation :
A neutral atom of phosphorous has 15 electrons.
The given electronic configuration is incorrect.
The reason is, According to Aufbau principle, the electrons will be first filled in the sub-shell having lower orbital energy. As from the given configuration, 3p sub-shell has lower orbital energy than 4s sub-shell. So, the electrons will be filled in 3p sub-shell first. Hence, the ground state electronic configuration of neutral atom of phosphorous is,

<u>Answer 3 :</u>
Element Rubidium Magnesium Aluminium
Symbol Rb Mg Al
Group number 1 2 13
Number of valence 1 2 3
electrons
The order of general reactivity on the basis of number of valence electrons.
Rb > Mg > Al
Reason : The reactivity is determined by the number of electrons present in the outermost shell that means the element which have 1 valence electron will be more reactive because they can easily lose electrons.
First, we must find the total mass of CuBr₂:
Mass = 64 + 2 x 80
Mass = 224
Percentage mass of copper = mass of copper x 100 / total mass
Percentage mass of copper = (64 / 224) x 100
Percentage mass of copper = 28.45%
Answer:
<em><u>Glass that will sink</u></em>
- alkali zinc borosilicate with a density of 2.57 g/mL in a solution with a density of 2.46 g/mL
- potash soda lead with a density of 3.05 g/mL in a solution with a density of 1.65 g/mL
<em><u>Glass that will float</u></em>
- soda borosilicate with a density of 2.27 g/mL in a solution with a density of 2.62 g/mL
- alkali strontium with a density of 2.26 g/mL in a solution with a density of 2.34 g/mL
<em><u>Glass that will not sink or float</u></em>
- potash borosilicate with a density of 2.16 g/mL in a solution with a density of 2.16 g/mL
Explanation:
Density is the property of matter that states the ratio of the amount of matter, its mass, to the space occupied by it, its volume.
So, the mathematical expression for the density is:
By comparing the density of a material with the density of a liquid, you will be able to determine whether object will float, sink, or do neither when immersed in the liquid.
The greater the density of an object the more it will try to sink in the liquid.
As you must have experienced many times an inflatable ball (whose density is very low) will float in water, but a stone (whose denisty is greater) will sink in water.
The flotation condition may be summarized by:
- When the density of the object < density of the liquid, the object will float
- When the density of the object = density of the liquid: the object will neither float nor sink
- When the density of the object > density of the liquid: the object will sink.
<em><u>Glass that will sink</u></em>
- alkali zinc borosilicate with a density of 2.57 g/mL in a solution with a density of 2.46 g/mL, because 2.57 > 2.46.
- potash soda lead with a density of 3.05 g/mL in a solution with a density of 1.65 g/mL, because 3.05 > 1.65.
<u><em>Glass that will float</em></u>
- soda borosilicate with a density of 2.27 g/mL in a solution with a density of 2.62 g/mL, because 2.27 < 2.62.
- alkali strontium with a density of 2.26 g/mL in a solution with a density of 2.34 g/mL, because 2.26 < 2.34.
<em><u>Glass that will not sink or float</u></em>
- potash borosilicate with a density of 2.16 g/mL in a solution with a density of 2.16 g/mL, because 2.16 = 2.16