Answer:
The artifact is 11,460 years old.
<u>Explanation</u>:
Given that,
The half life of the carbon-14 is 5730 years and we are left with 255 of the sample of wood from an arti-fact.
So it takes 5730 years for the sample to reduce into half
Initially there will be 100% of the sample so
after first 5730 years, the sample reduces into 50% percent
Now the left 50% sample will take another 5730 years to decay into half of its amount.
after next 5730 years the sample reduces into 25% percent
So totally after 2 half-life the sample reduces into 25%
That is (5730 +5730) years = 11460 years
Answer:
The shortest de Broglie wavelength for the electrons that are produced as photoelectrons is 0.81 nm
Explanation:
Given;
wavelength of ultraviolet light, λ = 270 nm
work function of the metal, φ = 2.3 eV = 2.3 x 1.602 x 10⁻¹⁹ J = 3.685 x 10⁻¹⁹ J
The energy of the ultraviolet light is given by;
The energy of the incident light is related to kinetic energy of the electron and work function of the metal by the following equation;
E = φ + K.E
K.E = E - φ
K.E = (7.362 x 10⁻¹⁹ J) - (3.685 x 10⁻¹⁹ J )
K.E = 3.677 x 10⁻¹⁹ J
K.E = ¹/₂mv²
mv² = 2K.E
velocity of the electron is given by;
the shortest de Broglie wavelength for the electrons is given by;
Therefore, the shortest de Broglie wavelength for the electrons that are produced as photoelectrons is 0.81 nm
Answer:
True
Explanation:
If it is at right conditions and correct time (night time most likely) they will all be visible
Answer:
1.)When you arrive from school and you smell cookies baking in the kitchen your brain will tell you that you are hungry and that you should go to the kitchen at that point your sense organs like your nose helps you to detect that something is baking(cookies)and your nervous system (brain)will tell you that you are hungry and it will command/direct your brain to go to the kitchen then for you to eat the cookies and drink the milk the digestive system is going go help you to chew,swallow and digest the food which has been taken and when you also run to the kitchen at the beginning your brain will direct your skeletal and muscular system because the skeletons and muscles work hand in hand,and when you finish your meal the body will circulate some nutrients or minerals from the food or snack taken to other parts of the body for energy.
2.)When you sleep the whole body is asleep except the heart which needs to continue circulating blood around the whole system and sometimes the brain may not rest when you are sleeping it may continue to do it's work that's why some people usually sleep walk or sleep talk,it means the brain is not at rest and still doing some things....Thank you for the question I hope it is very useful to you.
