Answer:
True
Explanation:
According to Aufbau's principle "sublevels with lower energies are filled up before those with higher energies".
Sublevels do not fill up in numerical order but there is a certain manner in which they are filled. The pattern is shown below:
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p e.t.c
We see that the 4s gets filled before the 3d sublevel.
Answer:
A gas is evolved
The ingredients can not be recovered
Explanation:
A chemical change is one in which a new substance is formed and it is not easily reversible.
One major ingredient used in cake baking is the baking powder or baking soda.
Baking a cake can be viewed as a chemical change. This is because, when the baking powder or soda is added in the presence of yeast, carbon dioxide gas is evolved as tiny bubbles of gas which makes the cake light and fluffy. Heat is equally given off in the process. The baking powder and other cake ingredients can not be recovered, hence, we can conclusively assert that a chemical change has taken place.
I’m not 100% positive but quartz would make sense
Answer:
Heating of the liquid water in a microwave.
Explanation:
Radiation is a form of heat transfer process that does not require a material medium rather it travels through space or vacuum in the form of electromagnetic waves or radiation. Heat transfer by radiation occurs in the form of microwaves, infrared radiation, visible light, or another form of electromagnetic radiation is emitted or absorbed. Some common examples of heat transfer by radiation is the warming of the Earth by the Sun, the warmth one experiences while sitting by the campfire, or the heating up of foods in a microwave.
Black bodies or surfaces are good absorbers as well as emitters of radiation. On the other shiny or white surfaces are poor radiators of heat.
From the above discussion on radiation, it can be seen that when the chemist takes the liquid and heats it in a microwave, the heat absorbed by the liquid to change to gaseous state is transferred through radiation.
Answer:
the concentration of bicarbonate is <em>[HCO₃⁻] = 0,03996 M </em>and carbonate is <em>[CO₃²⁻] = 3,56x10⁻⁵ M.</em>
Explanation:
Carbonate-bicarbonate is:
HCO₃⁻ ⇄ CO₃²⁻ + H⁺ With pka = 10,25
Using Henderson-Hasselbalach formula:
pH = pka + log₁₀![\frac{[CO_{3}^{2-}]}{[HCO_{3}^-]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BCO_%7B3%7D%5E%7B2-%7D%5D%7D%7B%5BHCO_%7B3%7D%5E-%5D%7D)
7,2 = 10,25 + log₁₀
8,91x10⁻⁴ = <em>(1)</em>
Also:
0,040 M = [CO₃²⁻] + [HCO₃⁻] <em>(2)</em>
Replacing (2) in 1:
<em>[HCO₃⁻] = 0,03996 M</em>
Thus:
<em>[CO₃²⁻] = 3,56x10⁻⁵ M</em>
I hope it helps.
