Answer:
B
Explanation:
Heating a piece of iron until it glows.
I'm not sure what it asks, but it answers
- how many protons are in the nucleus
- how many electrons are in the atom
- where it sits in the periodic table
- If the periodic table is divided in the modern way, it gives a good indicator of whether you are speaking about a metal, a non metal or neither.
Answer:
Energy should be saved and controlled as it is better for the environment. Excess use of energy of any kind can be disastrous. For example, a kind of energy is stored in the food. If excess food is consumed and wasted, then the country and other people will have to face consequences of it. Malnutrition will rise.
Another kind of energy is the energy in the fuel. If fuel consumption is not controlled then in the near future the resources for the making of fuel will be depleted.
Answer:
The partial pressure of neon in the vessel was 239 torr.
Explanation:
In all cases involving gas mixtures, the total gas pressure is related to the partial pressures, that is, the pressures of the individual gaseous components of the mixture. Put simply, the partial pressure of a gas is the pressure it exerts on a mixture of gases.
Dalton's law states that the total pressure of a mixture of gases is equal to the sum of the pressures that each gas would exert if it were alone. Then:
PT= P1 + P2 + P3 + P4…+ Pn
where n is the amount of gases present in the mixture.
In this case:
PT=PN₂ + PAr + PHe + PNe
where:
- PT= 987 torr
- PN₂= 44 torr
- PAr= 486 torr
- PHe= 218 torr
- PNe= ?
Replacing:
987 torr= 44 torr + 486 torr + 218 torr + PNe
Solving:
987 torr= 748 torr + PNe
PNe= 987 torr - 748 torr
PNe= 239 torr
<u><em>The partial pressure of neon in the vessel was 239 torr.</em></u>
Answer:
16.5 days
Explanation:
Given that:
Half life = 26.5 days
Where, k is rate constant
So,
The rate constant, k = 0.02616 days⁻¹
Using integrated rate law for first order kinetics as:
![[A_t]=[A_0]e^{-kt}](https://tex.z-dn.net/?f=%5BA_t%5D%3D%5BA_0%5De%5E%7B-kt%7D)
Where,
![[A_t]](https://tex.z-dn.net/?f=%5BA_t%5D)
is the concentration at time t
![[A_0]](https://tex.z-dn.net/?f=%5BA_0%5D)
is the initial concentration
Given:
35.0 % is decomposed which means that 0.35 of is decomposed. So,
![\frac {[A_t]}{[A_0]}](https://tex.z-dn.net/?f=%5Cfrac%20%7B%5BA_t%5D%7D%7B%5BA_0%5D%7D)
= 1 - 0.35 = 0.65
t = 7.8 min
![\frac {[A_t]}{[A_0]}=e^{-k\times t}](https://tex.z-dn.net/?f=%5Cfrac%20%7B%5BA_t%5D%7D%7B%5BA_0%5D%7D%3De%5E%7B-k%5Ctimes%20t%7D)
<u>t = 16.5 days.</u>
