How long is a microcentury in minutes? Note that 1 century is 100 years and 1 year is 365.25 days.

Q: the earth is 4.6 billion years old but human civilization the building of cities begin only about…

A: The fraction of age of human civilization to the age of earth is,

Q: Half-life is the period of time it takes for the amount of a radioactive substance to decrease by…

A: The time dilation equation is, τ=τ01-v2c2 Here, the total life is τ0,

Q: If there were originally 400 grams of carbon-14 in an object, how many grams would remain after…

A:

Q: For questions 69-70, consider the following: Uranium (45°U) decays to lead (20 Pb) with a half-life…

A: Given data The half-life is given as t1/2 = 700 million years = 700 x 106 years The number of a lead…

Q: A sample from a meteorite that landed on Earth has been analyzed, and the result shows that out of…

A: N=N0e-λt→1 T12=ln2λ ⇒λ=ln2T12=0.6931.3×109=0.533×10-9years-1

Q: 24.) Consider cobalt-60 with a half-life of 5.25 years. How many years will it take for its activity…

A:

Q: A particular isotope has a​ half-life of 1700 years. If you start with 1 kilogram of this​ isotope,…

A:

Q: A sample of F-18 has an initial decay rate of 1.5 x 10/s. How long will it take for the decay rate…

A: Initial decay rate, A=2.5×103/s Final decay rate, A0=1.5×103m/s Half-life of F-18 = 1.83 hour

Q: Fill in all the missing information. (i) 216Rn → He + ? (ii) ?-je + V

A: Alpha decay is a radioactive decay, in which unstable atomic nucleus emits an alpha particle and…

Q: How manyy microns make up 1.0km. What fraction of a centimeter equals to 1 micron How many microns…

A:

Q: The isotope carbon-14, 14/6C, is radioactive and has a half-life of 5 730 years. If you start with a…

A:

Q: What is the wavelength (in kilometers) of the 56,500-Hz radio wave used clocks and wristwatches?…

A:

Q: A sample of carbon-14 has a mass of 2.0 × 10–6 g. Carbon-14 has a half-life of 6000 years. How much…

A: Given  The mass or amount of carbon-14 is Ao = 2.0 × 10–6 g. The half-life time is h = 6000 years.…

Q: (20)The half-life of Carbon-14 is 5700 years.  If a 16 gram sample is found in a rock layer known to…

A: N(t)=No(0.5)t/h  h= half life N(t)=16 g t=42000 years h=5700 years we have to find No

Q: If a sample of pennies had 75 heads and 25 tails out of 100, how many half-lives have passed?

A: Total 100 In first half life 100/2=50 In second half life 50/2=25

Q: a parent isotope has a half-life of 500,000 years. if a rock contained 10mg of the parent isotope…

A: Write the expression for the quantity left after time t. Here, No represents the original quantity,…

Q: 1) How massive would Earth had been if it had accreted hydrogen compounds in addition to the sme…

A: It is required to calculate how massive would Earth had been if it had accreted hydrogen compounds…

Q: if the amount of the parent isotope in the original sample of a rock had been 48 grams, about how…

A:

Q: Based on stellar nucleosynthesis, which heavy element is formed from silicon fusion?

A: based on stellar nucleosynthesis, the helium burns to produce havier elements then continues for 1…

Q: A radioactive isotope has a half-life of 1.2 billion years. As measured by the presence of the…

A:

Q: 4. Early life on Earth formed in h. late September 5. Cambrian explosion would occur in f. mid…

A: 6) The Triassic Period (252-201 million years ago) 7)around 300,000 years ago. on that time 8)The…

Q: Describe, The Millikan's oil drop experment, ?

A:

Q: The half life of C-14 is 5730 years.  What percentage of C-14 remains 4850 years after a living…

A:

Q: The half-life of Carbon-14 is 6,000 years. How old is an object that started with 10,000 Carbon-14…

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Q: why is it pie - (pie/6)?

A: SHM: A particle accomplishes SHM when it oscillates in a straight line periodically in such a way…

Q: An intelligent alien living on a planet in the solar system orbiting Alpha Centauri, the nearest…

A:

Q: A rock sample contains a radioactive isotope that has a half-life of 10,000 years. One-fourth (25%)…

A:

Q: Suppose that a gram of antimatter came into contact with a 10 grams of matter, the amount of mass to…

A: When antimatter and matter comes in contact with each other the annihilate each other. 1 gram of…

Q: The​ half-life of​ carbon-14 is 5600 years. If a piece of charcoal made from the wood of a tree…

A: Given: half life  t1/2=5600 yearslet initial amount = Aofinal amount = 68% of Ao=0.68 Ao

Q: iven that the half-life of carbon-14 is 5,730 years. Consider a sample of fossilized wood that when…

A: Law of radioactive decay is N=N0e-λt where N is the amount left after passage of time t…

Q: of the 90N object ?

A: We know that the   weight of the object is given as  W = mg  where W is the weight of the object  m…

Q: How many Hydrogen atoms have to be transformed by following nuclear reaction to produce an energy of…

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Q: North America and Europe are moving apart at a rate of 2.5 cm/yr. They are now separated by 5,340…

A:

Q: How do we write one hundred nano- (100 times one-billionth)? 102 ✕ 10−9 = 10   We write ten…

A: One hundred milli- 102×10-3=10(2-3)=10-1=0.1 One hundred micro- 102×10-6=10(2-6)=10-4=0.0001 Ten…

Q: Calculate the time constant of the RC-circuit depicted here

A:

Q: Carbon-14 is a radioactive element with a half-life of about 5730 years. Carbon-14 is said to decay…

A: The formula for the decay constant is: Substitute the known values and solve.

Q: What is critical density? What is its estimated value?

A: The critical density is the value at which the universe is in equilibrium (balance) and expansion is…

Stellar evolution

We may see thousands of stars in the dark sky. Our universe consists of billions of stars. Stars may appear tiny to us but they are huge balls of gasses. Sun is a star of average size. Some stars are even a thousand times larger than the sun. The stars do not exist forever they have a certain lifetime. The life span of the sun is about 10 billion years. The star undergoes various changes during its lifetime, this process is called stellar evolution. The structure of the sun-like star is shown below.

Red Shift

It is an astronomical phenomenon. In this phenomenon, increase in wavelength with corresponding decrease in photon energy and frequency of radiation of light. It is the displacement of spectrum of any kind of astronomical object to the longer wavelengths (red) side.