For radioactive materials with short half-lives, you use a very sensitive calibrated detector to measure how many counts per second it is producing. Then using the exact same set up you do the same at a latter time. You use the two readings and the time between them to determine the half-life. You don’t have to wait exactly a half-life, you can do the math with any significant time difference. Also, you don’t need to know the absolute radioactivity, as long as the set up is the same you only need to know fraction by which it changed.
For radioactive materials with long half-lives that won’t work. Instead you approach the problem differently. You precisely measure the mass of a very pure sample of the radioactive material. You can use that to calculate the number of atoms in the sample. Then you put the sample in a counter that is calibrated to determine the absolute number of disintegrations happening in a given time. Now you know how many of them are disintegrating every second. You use the following equations:
Decays per Second = (Number of Atoms) x (Decay Constant)
Half-life = (Natural Log of 2) / (Decay Constant)
And you can calculate the half-life
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What is the function of a carbohydrate?
Answer:
to provide energy, store energy, build macromolecules, and spare protein and fat for other uses
Explanation:
Carbohydrates are the sugars, starches and fibers found in fruits, grains, vegetables and milk products. Though often maligned in trendy diets, carbohydrates —one of the basic food groups are important to a healthy diet
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What was the ratio of pea plant offspring with green pods to offspring with yellow pods in Mendel's second breeding?
Mendel found that 166 of the plants bore only yellow peas, and each of the remaining 353 plants bore a mixture of yellow and green peas in a 3:1 ratio
Diffusion & osmosis account for much of the ____________transport at the cellular level.
When reproduction involves two parents, which two statements describe the offspring?
A. Offspring differ genetically from one another.
B. Offspring differ genetically from both parents
C. Offspring are genetically identical to one another.
D. Offspring are genetically identical to one parent.
Answer:
I think it's B.
Sorry if i'm wrong tho
Answer:
A and B
Explanation:
I just did the test and i got them right
i need help with this so if your good at embryology pleaseee help me i have a D:( :)
Answer:
Tails and gill slits
Explanation:
Brainliest
How is the rate of diffusion affected by:
(a) Temperature?
(c) Surface area to volume ratio?
The following experiment was set up to
Answer:
a
Explanation:
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2 ATP are produced at letter(s):
A) B
B) D
C) AB
D) Both B & D
Answer:
A
Explanation:
Which of the below best describe Mendel's Principle of Dominance and
Recessiveness?
Two factors for a charaterisitic seperate during the formation of egg and sperm.
The factors for different traits are distributed to the gametes independently
O One factor in a pair may mask the effect of another.
O Recessive traits will mask or hide the dominant trait.
Answer:
My answer is, One factor in a pair may mask the effect of others.
Explanation:
I may be wrong. Hope this helps!
In cells, the enegy available in food is used to make an energy-rich compound called
In plants, which process requires lighted conditions?
Answer:
photosynthesis
Explanation:
Plants make sugars in the presence of sunlight in a process called photosynthesis.
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Answer:
photosynthesis
Explanation:
Only males carry the Y chromosome, does your mother's DNA have any ell
chromosome?
Answer: Females have the X chromosome
Explanation:
What happens to the glucose produced in photosynthesis? Select ALL that apply a The glucose is modified & stored in the plant for later use b The glucose is used directly as energy by the chloroplast c The glucose is moved to the mitochondria where it will be converted into energy d The glucose is released as a waste product
Answer:
The glucose produced in photosynthesis is altered and processed for later use in the plant. The glucose is used directly by the chloroplast as energy. The glucose is transferred to the mitochondria to be transformed into energy.
Explanation: Among the four statements, three of the statements are correct . The fourth statement which states that "the glucose is released as a waste product " is incorrect . This is because oxygen is used as the waste product rather than glucose.
All the three statements are correct about glucose in photosynthesis . The plant uses glucose, with most of it transformed into other carbohydrates, such as starch and cellulose.
A mechanism in which, in the mitochondria of all cells, chemical energy (glucose) is converted into an energy currency (ATP). Glucose and oxygen are converted into water and carbon dioxide. There are two forms namely, aerobic which requires oxygen and Anaerobic which does NOT require oxygen.
Photosynthesis is the process of preparing food in the presence of sunlight, water, and carbon dioxide to make glucose and release oxygen.
The use of glucose produced during photosynthesis is:
a. The glucose is modified & stored in the plant for later use
b. The glucose is used directly as energy by the chloroplast
c. The glucose is moved to the mitochondria where it will be converted into energy
Glucose pathway in plants:
Glucose is the primary source of energy, which is stored in the form of starch. The glucose is broken down through cellular respiration to yield ATP. Glucose is directly used as a source of energy by chloroplasts. Chloroplasts require glucose to convert light energy into chemical energy to carry out photosynthesis. Mitochondria are the powerhouse of the cells, which converts glucose into ATP via cellular respiration. The glucose and oxygen are converted into water and carbon dioxide.To know more about the roke of glucose in photosynthesis, refer to the following link:
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How does the Alaska blackfish survive in waters with temperatures of 5ºF?
Answer: The Alaska blackfish survives in water with temperatures of 5ºF by producing chemicals that lower the freezing temperature of cellular fluids. This keeps the fluids of the fish from freezing, allowing it to survive.
Answer:
The Alaska blackfish survives in water with temperatures of 5ºF by producing chemicals that lower the freezing temperature of cellular fluids. This keeps the fluids of the fish from freezing, allowing it to survive.
Explanation:
Define sickle cell.
Who is a sickler?
Answer:
Sickle cell disease is an inherited blood disorder that turns normal, round blood cells into misshaped cells that look like sickles or crescent moons. These sickled cells can get stuck in blood vessels, blocking blood flow and causing severe pain as well as damage to organs, muscles, and bones. Sickle cell disease is inherited, passed from parent to child. Children with sickle cell disease have two defective genes, one from each parent. A child born with sickle cell trait inherited one defective gene from one parent, and a normal gene from the other parent. These children don't have sickle cell disease but are carriers of the defective gene and may pass it on to their children.
hope this helps!!Explanation:
The volcanoes can be seen on the topographic map as tall peeks. How many volcanic peaks higher
than 7000 feet can be seen on this map.
Answer: 2
Explanation:
Each line represents an increase in height of 1000ft.
And the volcano peaks are the circles with no other concentric lines inside (meaning that does not grow anymore, so it is the peak).
We can see that the peak of the top volcano has 13 lines, so it is around 13,000 ft high.
The bottom volcano has also 13 lines, so it is also around 13,000 ft high, then in the image we can see two volcanos higher than 7000ft.
What are electron energy levels? Where are they located?
The electrons surrounding an atom are located in regions around the nucleus called “energy levels”. An energy level represents the 3-dimensional space surrounding the nucleus where electrons are most likely to be. The first energy level is closest to the nucleus.
Answer: Located in regions around the nucleus.
Explanation: Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. As you go farther from the nucleus, electrons at higher energy levels have more energy. The electron energy levels are an atom located in regions around the nucleus. An energy level represents the 3-dimensional space surrounding the nucleus where electrons are most likely to be. The first energy level is closest to the nucleus. The second energy level is a little farther away than the first.
You have identified a plant in your garden with a new flower color. You want to determine if this phenotype is dominant or recessive. Which cross would tell you this? You have identified a plant in your garden with a new flower color. You want to determine if this phenotype is dominant or recessive. Which cross would tell you this? crossing the new plant to one you know has the dominant trait crossing the plant to one you know has the recessive trait selfing the plant sequencing the DNA for the trait crossing the plant to a plant of the same type of any color
Answer:
crossing the plant to one you know has the recessive trait
Explanation:
The correct procedure would be to cross the identified plant with the same plant that has the recessive trait.
The phenotypes of the progeny from the cross will give an indication of the dominance or recessive of the phenotype. If all the progeny from the cross produce the same flower color as that of the identified plant, it means the phenotype is dominant. Otherwise, it is recessive.
The procedure is called test-crossing in genetics.
Why does the author present Redi’s experiments first, followed by Pasteur’s experiments?
Redi’s experiments were more important than Pasteur’s.
The author wanted to present the experiments in historical sequence.
Redi’s experiments completely changed the belief in spontaneous generation.
The author wanted to focus on the maggots that were found in the rotted meat.
Answer:
ThE aNsWeR iS b
Explanation:
Bc I gOt It RiGhT
Answer:
B
Explanation:
The endosymbiotic theory of eukaryote evolution states that organelles in eukaryotic cells are derived from prokaryotes. Which statement is the strongest evidence in support of the endosymbiotic theory?
A Eukaryotic organelles are similar in size and shape to prokaryotes.
B Eukaryotic organelles can reproduce though sexual reproduction.
C Eukaryotic organelles stop functioning outside of a plant cell.
D Eukaryotic organelles contain DNA similar to prokaryotic DNA.
Answer:
C. Eukaryotic organelles stop functioning outside of a plant cell.
Explanation:
Because Certain functions are carried out within different structures of the cell. These structures ... Organelles in Eukaryotic Cells. 5. Model 3 – Animal Cell vs. Plant Cell. Plant cells have a cell wall, a large central vacuole, chloroplasts, and other specialized ... Chloroplasts are the organelles that carry out photosynthesis. ... Despite differences in structure and function, all living cells in multicellular organisms .It is these cells, tissues, and organs that carry out the dramatic lives of plants. Plant Cells. Plant cells resemble other eukaryotic cells in many ways. ... are enclosed by a plasma membrane and have a nucleus and other membrane-bound organelles. ... The different types of plant cells have different structures and functions. Hope this helps you!
Which process begins the formation of sedimentary rock?
A the movement of sediment
B the cementation of rock sediment
C the breakdown of rock into sediment
D the buildup of sediment in one location
Answer:
the answer is c
the formation of sediment rock is formed due to the breakdown of rock into sediment
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Answer:
answer is C.... ......
describe what isomer are and how they apply to carbohydrates
Answer: they all have the same chemical formula but differ structurally and chemically. Disaccharides form when two monosaccharides undergo a dehydration reaction (a condensation reaction); they are held together by a covalent bond.
Explanation:
The phenomenon of exhibiting similarity in the chemical formula but differs in the compound’s structure is termed isomerism. The particular compounds that exhibited such similarity are referred to as isomers.
Isomers are classified into two major categories namely structural and stereoisomers. Isomers apply to carbohydrates that are described as follows:
Glucose, fructose, and galactose are some of the examples of monosaccharide isomers They all tend to have the same chemical formula but they are varied in terms of structure and chemical nature.Thus, we can conclude that the isomers have the same molecular formula but varying structures. Further, how the isomers apply to carbohydrates is also discussed.
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If you increase the intensity of light, the amount of photosynthesis decreases.
Answer:
TRUE
Increasing the light intensity increases the rate of photosynthesis
Answer:
true
Explanation:
the law of mass action suggests that
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A patient has pain in abdomen. The doctor thinks the patient’s gall bladder has problem and it has stones in it. Doctor advise patient to go for ultrasound examination. This test shows stone and swelling in gall bladder. The doctor says that patient has cholecystitis (gall bladder problem)
A. What is doctor’s diagnosis?
B. What evidence does the doctor use?
Explanation:
A) doctor's diagnosis that the patient's gallbladder has problem and it has stones in it.
B) after ultrasound, the test shows stone and swelling in the patient's gallbladder. Thai gives an evidence that the patient ihas cholecystitis.
hope it will help.....
Living organisms all have DNA and RNA which are both Which term best completes the sentence? lipids proteins carbohydrates nucleic acids
Your answer should be D. Nucleic Acids.
Answer:
your answer is nucleic acids
Explanation:
A student found a grasshopper in their backyard and wanted to take it to school to show the teacher the next day. The student put the grasshopper in a sealed container overnight to keep it from hopping away. When the student opened the container the following day, the grasshopper was dead. Which best describes what organelle in the grasshopper’s cells was unable to perform properly for the grasshopper to stay alive as a result of being kept in a sealed container overnight?
Answer:
b
Explanation:
3. Consider the technology behind each type of
microscope. Why can light microscopes produce
images in their natural color, while scanning
electron and transmission electron microscopes
only produce grayscale images?
Answer:
See the answer below
Explanation:
The light microscope uses visible light to produce images of objects on its slide while the electron microscope uses beams of electrons to project the image of specimens. Color is a property of photons of light, hence, the light microscope is able to produce images of specimens in their natural colors
The areas of the specimen on an electron microscope in which the beams of electron pass through usually appear white while other areas appear black. Hence, the electron microscopes can only produce grayscale images of specimens unless a false color is added to make the images visually appealing.
Scanning electron and transmission electron microscopes only produce grayscale images because electrons do not have colors.
Electrons can emit energy in the form of light when they return to a lower energy level. The color depends on the difference in energy between the two different levels.The color is a property of light, thereby light microscopes that use visible light to generate images can produce colored images.Conversely, scanning and transmission electron microscopes use an electron beam to image a sample, which does not record any color value.In conclusion, scanning electron and transmission electron microscopes only produce grayscale images because electrons do not have colors.
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Which three types of waste do humans dump in the water? Select THREE choices. *
A. fertilizers
B. sewage
C. salt
D. pesticides
Answer:
Sewage is the answer of this
which bone would a forensic anthropologist analyze to identify a victim as male or female?
Femur
Phalanges
Cervical vertebrae
Metatarsals
Answer:
Femur
Explanation:
I just took the test and it was correct. Generally they can tell by the pelvis but that's not an answer choice so femur is closet to it as they are connected and femur can be used to identify the difference too.
When can two parent plants with purple flowers produce
offspring with white flowers?
Answer:
if purple is the dominant allele (P) and white is the recessive allele (p) then it would be possible if both parents had the genotype Pp, then it would be possible for both parents to pass on the recessive gene (p) and have offspring with white flowers
Explanation: