The positive effect of using chemistry is the generation of energy without fossil fuels.
Chemistry is the branch of science that deals with the study of the nature, properties and composition of matter as well as the changes that matter undergoes. Chemistry has really contributed positively to the advancement of the society.
Lately, there has been a lot of emphasis on alternative sources of energy apart from fossil fuels. One such options is the use of hydrogen fuels. Chemistry has been at the forefront of this research.
Hence, one positive effect of using chemistry is that energy can be generated without burning fossil fuels.
Learn more: brainly.com/question/2192784
Answer:For Fe
Z=26
Explanation:
1s2 2s2 2p6 3s2 3p6 4s2 3d6
Are there 26 electrons here? Why should there be 26?
So going back to the inert gas, argon ( Z=18 ), we get
[Ar] 4s2 3d6
Make sure to check your work by counting the electrons you have
answer
When an electron temporarily occupies an energy state greater than its ground state, it is in an excited state. An electron can become excited if it is given extra energy, such as if it absorbs a photon, or packet of light, or collides with a nearby atom or particle
Answer:
2.79 mg iron-59 is left in the sample after 267 days.
Explanation:
Given that:
Half life = 44.5 days
Where, k is rate constant
So,
The rate constant, k = 0.0156 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 = 180 mg
Time = 267 days
So,
![[A_t]=180\ mg\times e^{-0.0156\times 267}](https://tex.z-dn.net/?f=%5BA_t%5D%3D180%5C%20mg%5Ctimes%20e%5E%7B-0.0156%5Ctimes%20267%7D)
![[A_t]=180\times e^{-0.0156\times 267}\ mg](https://tex.z-dn.net/?f=%5BA_t%5D%3D180%5Ctimes%20e%5E%7B-0.0156%5Ctimes%20267%7D%5C%20mg)
![[A_t]=2.79\ mg](https://tex.z-dn.net/?f=%5BA_t%5D%3D2.79%5C%20mg)
<u>2.79 mg iron-59 is left in the sample after 267 days.</u>
When a half-life passes, only half of the mass of the sample stays. So to get to 25 g from 200, let's see how much half-lives will pass.
200÷2=100
100÷2=50
50÷2=25
The answer to that is 3 half-lives, or
3 × 5730 = 17190 years
