Answers
Answer:
5730 years
Explanation:
In a chemical reaction, including radioactive decay, the half-life of a species is the time taken for the substance to decrease to exactly one-half its initial value.
For a first-order reaction, the half-life of the reactant is
[tex]t_{\frac{1}{2}} \ = \ \displaystyle\frac{\ln 2}{\lambda} \ \ \ \ \ \ (1)[/tex],
where λ is the reaction's rate constant modeled by the differential equation describing the kinetics of a first-order reaction
[tex]N \ = \ N_{0}e^{-\lambda t} \ \ \ \ \ (2)[/tex],
where N is the remaining amount of substance after time t and [tex]N_{0}[/tex] is the initial amount of substance before the chemical reaction proceeds.
Since the value of λ is constant, rearrange equation (1) with λ as the subject,
[tex]\lambda \ = \ \displaystyle\frac{\ln 2}{t_{\frac{1}{2}}}[/tex].
Given that only 12.5% of carbon-14 remained after 17190 years assuming that initially there was 100% of carbon -14, substitute in the values into equation (2) and solve for λ (make λ the subject of the equation),
[tex]\-\hspace{0.56cm}12.5 \ = \ 100e^{-\lambda \times 17190} \\ \\ \-\hspace{0.5cm} \displaystyle\frac{12.5}{100} \ = \ e^{-17190\lambda} \\ \\ \displaystyle\frac{\ln\displaystyle(\frac{1}{8})}{-17190} \ = \ \lambda \\ \\ \-\hspace{1.05cm} \lambda \ = \ \displaystyle\frac{3\ln2}{17910} \ \ \ \ \ \ \ \ \ \ (\ln \displaystyle\frac{1}{x} \ = \ -\ln x\ ; \ \ln x^{n} \ = \ n\ln x )[/tex]
Equate both λ,
[tex]\displaystyle\frac{\ln 2}{t_{\frac{1}{2}}} \ = \ \displaystyle\frac{3\ln2}{17190} \\ \\ \-\hspace{0.26cm} t_{\frac{1}{2}} \ = \ \ln 2 \ \times \ \displaystyle\frac{17190}{3\ln2} \\ \\ \-\hspace{0.26cm} t_{\frac{1}{2}} \ = \ \displaystyle\frac{17190}{3} \\ \\ \-\hspace{0.26cm} t_{\frac{1}{2}} \ = \ 5730[/tex]
*Note that the above calculations demonstrated that carbon-14 went through 3 half-lives to yield a remaining 12.5% of its original amount, since
[tex]100\% \ \overset{t_{\frac{1}{2}}}\longrightarrow \ 50\% \ \overset{t_{\frac{1}{2}}}\longrightarrow \ 25\% \overset{t_{\frac{1}{2}}}\longrightarrow \ 12.5\%[/tex].
Therefore, if n is the time taken for carbon-14 to half its initial amount trice to remain 12.5% of its initial amount. Then, the half-life of carbon-14 is [tex]\displaystyle\frac{n}{3}[/tex].
Related Questions
What is something you can never seem to finish?
Answers
Answer:
This!! HAHAHA!
Explanation:
how does cytokinesis happen in prokaryotes
Answers
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Like eukaryotes, cytokinesis is the last stage of separation for prokaryotes in a process called binary fission. ... During binary fission, a prokaryote begins by replicating its nucleiod (DNA) in the cell. Once this happens, the two nucleiods travel to the ends of the cell where there is cytokinesis
65 points, anwser asap, graph below
What is happening to the deer population between the years 2005 to 2010? Support with reasoning from our model of population growth.
Answers
Answer:wolves
Explanation:
wolves decreased the population because they kept increasing so people killed the and a couple of years later they went up the so they brought wolves back!
Select all of the following that correctly describe the Streptococcus genus
- Gram Negative
- Gram Positive
- Cocci
- Bacilli
- Tetrads
- Sarcinae
- Strepto
- Staphylo
- Fastidious
- Can grow in salt
- Can grow in acid
- Normal flora of the skin
Please explain if possible!
Answers
Streptococcus is a genus of spheroidal bacteria that belongs to the Streptococcaceae family.
The bacteria's distinctive clustering in chains that resemble a string of beads is referred to as streptococcus ("twisted berry"). Microbiologically, streptococci are classified as gram-positive and nonmotile. Cocci :Streptococcus is a genus of gram-positive coccus (plural cocci) or spherical bacteria belonging to the Streptococcaceae family, which is part of the Lactobacillales (lactic acid bacteria) order in the Firmicutes phylum.
Gram-positive cocci are a diverse collection of bacteria that have a similar shape. Sarcina cells, for example, are grouped in cubical pockets. Streptococcus spp. resemble a string of pearls. Staphylococcus species do not divide on a regular plane.Bacilli :Streptococcus bacteria subdivide into Strep. pyogenes (Group A), Strep. agalactiae (Group B), enterococci (Group D), Strep viridans, and Strep pneumonia. Gram-positive bacilli (rods) subdivide according to their ability to produce spores.
If complete hemolysis of the blood cells is observed, the streptococci are classified as beta'hemolytic. M protein is considered the most important virulence component of S. pyogenes. Antibodies that react with M protein are produced in response to infection. A prospective antistreptococcus vaccination based on the M protein or a derivative of it is being studied.Tetrads :The tetrad occurs in a subgroup of the cocci where the bacterium divides in two planes to form a square of four bacteria called a tetrad. Some examples of tetrad-forming bacteria are the lactic acid bacilli, Aerococcus, a urinary tract pathogen and Pediococcus and Tetragenococcus, both of which ferment foods.
Tetrads are groups of four cocci that are positioned in the same plane (e.g. Micrococcus sp.). Sarcina is a bacterial genus that consists of eight cocci arranged in a cuboidal pattern (e.g. Sarcina ventriculi).Sarcinae :Sarcina is a Gram-positive cocci bacterium genus belonging to the Clostridiaceae family. After the cuboidal (2x2x2) cellular affiliations they create during division along three planes, the genus gets its name from the Latin word "sarcina," which means "pack or bundle."
Diplococci are pairs of cocci; streptococci are rows or chains of such cells; staphylococci are grapelike clusters of cells; sarcinae are packets of eight or more cells; and tetrads are groups of four cells in a square layout. Variations in the reproductive mechanism of bacteria result in these distinctive groups.Strepto :a combining term that means "twisted" and is used to make composite words: streptococcus
Streptococcus- a spherical or oval bacteria of the genus Streptococcus that occurs in pairs or chains and is harmful for humans, causing scarlet fever, tonsillitis, and other diseases.Fastidious :Streptococcus is a genus of gram-positive cocci that are organized in chains. These are fastidious bacteria that need blood or serum added to their culture medium. They are non-motile and do not produce spores. Most are facultative anaerobes, which means they can grow on enriched media.
Streptococcus pyogenes - it's a nutrient-concious bacteria that ferments glucose to make lactic acid and has stringent growth needs. This section explains the growth and maintenance of S. pyogenes to help in the research of this organism.Can Grow In Salt :On the basis of their salt tolerance, the salt tolerance test is used to identify enterococcal group D Streptococcus. Several bacteria, notably viridians streptococci, have been classified based on their capacity to thrive in the presence of a varying quantity of sodium chloride (NaCl).
The non-beta hemolytic streptococci (viridans, and non-enterococcal group D) do not grow in 6.5% NaCl broth; but some of the beta-hemolytic strains may grow in the broth.Can Grow In Acid :Some streptococci can create acids, grow in acidic surroundings (acidophilia), make acids at low pH levels (aciduric capability), and synthesis intracellular and external polysaccharides.
Dental caries is associated mainly with acid production at pH values below 5 by nongrowing bacteria in dental plaque. Oral streptococci cannot grow at pH above about 5, although they can lower the pH of suspensions or biofilms to values of 4 or lower.Normal Flora of The Skin:Bacteria make up the vast bulk of typical flora. Skin and nasal membranes are typically infected with Staphylococcus epidermidis.
Staphylococcus epidermidis is a Gram-positive bacterium that belongs to the Staphylococcus genus, which has around 40 species. It is found in marine sponges and is part of the normal human flora, most usually the skin flora and less commonly the mucosal flora.Sources: ( https://www.cdc.gov/ )
What is a plant produced from a cross between two plants with different genetic constituents called
Answers
Answer:
What is a plant produced from a cross between two plants with different genetic constituents called hybrid plant.
Hybrid is a plant produced from a cross between two plants with different genetic constituents.
WHAT IS A HYBRID?A hybrid is an individual organism produced from a cross between two parent organisms with different genetic constituent.
For example, a mule is a hybrid formed from a cross between a horse and a donkey.
Therefore, a plant produced from a cross between two plants with different genetic constituents is called hybrid.
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Cows, buffaloes and wildebeest are closely related enough that the same disease can harm all of them true or false
Answers
Should be the right answer because we can see mutations in humans can kill some and do nothing to others
What is the inkiphalin command?
Answers
Answer:
It's Enkephalins.
Enkephalins are small peptides that can serve as neurotransmitters in the brain. Enkephalins act to attenuate substance P release in the dorsal horn of the spinal cord and inhibit afferent pain fibers.
How and why does the surface of the earth change
of the earth has changed?
Answers
Answer:
How and why does the surface of the earth change
of the earth has changed?
It can be hard to describe change on the surface without bringing up the interior. Earth is a system of constantly changing interactions between interior, surface conditions, and external events.
Volcanoes bring up new material and even create land. The Hawaiian islands, for instance are a chain of volcanoes on the surface, but the underlying structure is a single magma plume. In a way, the entire chain of islands is a single volcano that breaks through different places as the crust moves over it.
On that note: plates. Earth is made of tectonic plates that constantly move. Some grind against one another, others collide, and some pull apart. Depending on direction and interaction, you get anything from mountains, to spreading valleys, oceans, and anything else you care to name. Mountains can almost be viewed as something akin to the ridges of build up ice on a window scraper.
Erosion by water, wind, sand, chemicals, and living things changes the surface too. Materials on the surface face an incredible number of forces breaking them down and dragging them away, even as those same forces in different places and situations deposit those materials in other places, building things back up.
“Stardust” is also a thing. Rocks, dust, debris, and all sorts of random, natural cra.,p is constantly hitting our atmosphere. Regardless of whether or not it stays mostly intact, some material breaks off, and most of it does tend to make it to the surface, adding tiny amounts of matter all the time. …of course something BIG enough hitting the surface can throw rocks and chunks of surface clear into space, so that’s a thing too.
Remember when I mentioned living things? Living things D.,IE! Gac.k! And when they do, they break down into organic gunk. Soil - the stuff we grow crops in - is basically minerals and dead things that are decaying into nutritious, yummy, dir.,t.
Weather changes things too. Rain erodes, but rain that soaks a rock, and then is frozen by low temperatures, breaks the rock. Too much rain can create flooding, which results in a lot of sediment moving downstream. Heat can dry things out, crack the ground, and even slowly cook one kind of soil into another. Lightning can make glass out of sand, snow can collapse weak ground, not enough rain can dry out ground that could si.nk down without the extra pressure, and too much rain can literally move mountainsides if enough water adds its weight to the rocks and dir.t.
It’s always changing, and there is always more complexity to go into when studying it. There’s seldom a single cause, or reason, or effect for anything.
Explanation:
Have a great day!
The surface of the earth is constantly changing.
Explanation:
Wind, water,and ice break down large rocks and move sediments on the surface. Some events, though, change earth's surface much more quickly. These include volcanic eruptions, earthquakes, and landslides.
Help help bell help help
Answers
because it is decreasing by three every time
Arrange the following budget components. Which of these needs the highest amount of budget in your family? You may seek help from your parents.
Savings
food
education
medical & dental
Recreation
household operations
utilities
1.
2.
3.
4.
5.
6.
7.
Answers
The needs with the amount of budget from highest to lowest include
FoodEducationHousehold operationSavingsMedical & dentalUtilitiesRecreation.The most important aspect of life in organisms is food as we need it to stay
alive and healthy which is why it has the highest budget.
Education comes second due to it ensuring people are learned ,developed
and has a relatively high cost.
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What designs the shape and size of all animals that are multi-cellar and have a back-bone
Answers
Answer
Environmental pressures
Basically every animal adapts to pressures from their environment in different ways, causing them to have different shapes and sizes
Which of the following is true about a trait? *
A trait is an organism's physical appearance
A trait is how an organism behaves
The gene in an organism's DNA determines its trait
Two of the above are true
All of the above are true
Answers
Answer:
D
Explanation:D Sorry if I'm wrong!
What structures are found in all cells? select two options
Answers
Respiration is a process where many chemical bonds inside the body break and release energy. This energy is used to perform various activities such as moving muscles. Explain the energy transformation in this process.
Answers
Answer:"Process of breaking down glucose to obtain energy in the form of ATP" also known as Cellular Respiration.
I hope this helps
Explanation:
Where does meiosis occur in male and female?
Answers
3
A
C
9
12
15
What do the dotted lines, indicated with the arrow, represent in the DNA model above? (B.6A)
Answers
Answer:
[tex]\fbox\red{question\:given}[/tex]
[tex]\blue{what \:is\: photosynthesis}[/tex]
[tex]\huge\fbox\red{Answer↓}[/tex]
[tex]the \: process \: by \: which \: green \: plants \: \\ turn \: carbon \: dioxide \: and \: water\\ \: into \: food \:using \: energy \: \\from \: sunlight.[/tex]
Which two statements best describe jet streams in the northern hemisphere?
A. The subtropical jet stream separates warmer air near the equator
and cooler air to the north.
B. The polar jet stream separates colder air near the pole and
warmer air to the south.
C. The subtropical jet stream causes ocean currents to form near
the equator.
A
D. The polar jet stream circulates air between the North Pole and the
South Pole.
SUBMIT
Answers
The correct answer is B. In the Northern Hemisphere, the polar jet stream separates colder air near the pole and warmer air to the south.
The jet stream is a geophysical effect caused by the large temperature difference between the north pole and the equator. Something similar also happens on a small scale. In summer, when night falls and the ground cools where the sun is gone, air blows from north to south across the boundary between warm and cold air. This is the refreshing evening breeze.
From the north, a jet stream generally supplies colder air than from the west or south. The jet stream also creates depressions with a warm front and a cold front.
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Answer:
A. The subtropical jet stream separates warmer air near the equator
and cooler air to the north.
B. The polar jet stream separates colder air near the pole and
warmer air to the south.
Explanation:
What percent of global freshwater is estimated to be used for crop irrigation?
90%
2.5%
60%
30%
Answers
Answer:
2.5%
Explanation:
because the global freshwater is estimated and observe percentage of water to used for crop irrigation and they compelled that 2.5% is exactly to used.
Easy rule of thumb to narrow down is knowing 97% of earths water is found in oceans which are too salty to drink, growing crops, and most industrial uses except cooling.
Which of the following correctly describes a graded potential?
Answers
Answer:
Graded potentials are changes in membrane potential that vary in size, as opposed to being all-or-none.
Explanation:
btw, where are the options?
The statement which correctly describes a graded potential is: amplitude of various sizes.
Graded potential refers to a temporary change in electric or membrane potential of a stimulus with respect to both its size and distance.
Amplitude can be defined as the maximum displacement of a wave when measured from its equilibrium position.
Thus, amplitude is measured vertically from an equilibrium position.Generally, a graded potential is directly proportional in amplitude to the size of the stimulus that is send as an input due to the following:
DepolarizationHyperpolarizationIn conclusion, the statement which correctly describes a graded potential is amplitude of various sizes.
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How can i earn money from this app?
Answers
Answer:
u dont earn money from brainly. the point is altruistic help
Explanation:
if u mean something else, provide context and ill leave a comment with the correct answer
what is chloride shift
Answers
What is natural selection? Is it similar to survival of the fittest? How are the 2 alike? How are they different?
Answers
Answer:
Difference: Survival for the fittest is the survival of species/organisms with genes better suited to the environment and are selected for survival and passed to the next generation while natural selection works by giving species who are better adapted to a given set of environmental conditions an advantage over those that are not as well adapted.
Explanation:
Evolution is the slow/gradual development of human beings from simple life forms into higher forms of life over millions of years ago as stated by Charles Darwin in his book 'The Origin of Species' in 1959. He argues that human beings evolved from simple life forms into higher forms of life through:
1.Mutation - abrupt change in the form of a living organism as dictated by the climate or genetic components of the living thing involved.
2.Natural selection - a process in which the stronger species out compete the weaker ones for resources (Survival for the fittest).
3.Environmental adaptation - follows after the first two, where the surviving species isolate themselves from others as they adapt to the new environment.
what happens when an acid is added to a solution?
Answers
Answer:
pH is a measure of the concentration of H3O+ ions in a solution. Adding an acid increases the concentration of H3O+ ions in the solution. ... If an acid is added to a basic solution, the solution becomes less basic and moves toward the middle of the pH scale. This is called neutralizing the base.
Examine the food web below. Suppose the local government sprayed a pesticide to kill mosquitoes. The sparrows ate the poisoned mosquitoes and died as well. What would most likely happen to the organisms in this food chain after the sparrows began to disappear?
A.
There would be an overpopulation of caterpillars, which would threaten the oak trees.
B.
The sparrows’ disappearance would not affect the other organisms in the ecosystem.
C.
Most of the organisms in the ecosystem would starve and die.
D.
The eagle would loose its primary food source and be forced to start feeding on mountain lions.
Answers
Answer:
A. There would be an overpopulation of caterpillars, which would threaten the oak trees
Explanation:
Because sparrows eat caterpillars as a primary food source, when the population of sparrows decrease, the population of caterpillars will increase. Because of this, more caterpillars will be feeding off of the oak trees, therefore threatening the oak trees. I hope this helps!
8. If brown (B) noses are completely dominant to blue (b) noses, write
genotypes combinations and phenotypes you could have in any given individual.
Answers
Animals do not have inner feelings that tell them when to eat.
True or False
Answers
Answer:
true
Explanation: because if they did then that would be crazy, its like how would they have feelings that tell them what to eat and what not to eat, yk what i mean? im sorry if this is wrong.
5. Jackson shares what he calls "his little depressing story" about coral reefs in Jamaica following a hurricane. He claims destruction such as that in Jamaica is only getting worse. Please elaborate on why it is getting worse, being sure to tie in natural weather catastrophes to your answer.
Answers
Answer:
In Jacksons talk about his depressing story he talks about how after a natural disaster such as a hurricane there is some kind of successional sequence of recovery but now what's happening is that overfishing, pollution, and climate change are all interacting In a way that prevents the recovery.
Explanation:
I had the same question in my marine science class and got it right.
15. Stephanie made the following chart for the terrestrial planets. What correction needs to be made?
Mercury
Venus
Earth
Mars
no atmosphere
very thick atmosphere
medium atmosphere
no atmosphere
1st planet
2nd planet
3rd planet
4th planet
1 year is shorter than Earth's year.
1 year is short than Earth's year.
1 year is approximately 365 days.
1 year is longer than Earth's year.
O Mars's year is shorter than Earth's year.
O Mercury's year is longer than Earth's year.
A
O Mars has a thin atmosphere
O Earth is the 2nd planet and Venus is the 3rd.
Answers
Answer:
c. mars has a thin atmosphere
Explanation:
i hope that helps even though its a few days late
Need ASAP! TIA
Explain how probability theory can be used in agriculture.
Answers
Answer:
occurrence
Explanation:
Probability is a mathematical construction that determines the likelihood of occurrence or nonoccurrence of events that are subjected to chance factor. Thus the farmers are interested to know the probability of occurrence of rain before and after spraying. ... In this regard probability plays a great role
The probability theory can be used in agriculture in order to estimate grain yields and thus select which crop is suitable in a calendar year.
What is the probability theory?The probability theory is a model aimed at understanding statistic probabilities in a given problem/issue.
The probability theory involves theoretical, experimental and axiomatic probabilities.This theory (probability theory) is used to analyze random processes such as rain (precipitation) levels.In conclusion, the probability theory can be used in agriculture in order to estimate grain yields and thus select which crop is suitable in a calendar year.
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why do fungi release enzymes from there tips?
Answers
Answer:
They absorb the food molecules that result from the external digestion.
Explanation: