A radioactive substance has a half-life of 1.25 million years. What is the age of a rock in which 6.25% of the original radioactive atoms remain? 5 million years old 6.25 million years old 3.75 million years old6 2.5 million years old 1.25 million years old 625 thousand years old

Answers

Answer 1

Answer:

The age of the rock is 5 million years

Explanation:

Fraction of radioactive substance remaining = 6.25% = 625/10000 = 1/16

Number of half-lives undergone by the substance to leave behind 1/16 of the original sample

1/16 = (1/2) * (1/2) * (1/2) *(1/2)

Therefore, the substance have decayed 4 times

One half=life = 1.25 million years

Four half-lives = 4 * 1.25 million years = 5 million years

Therefore, the age of the rock is 5 million years


Related Questions

Two differences between hormones and the nervous system

Answers

Answer:

Hormones can be proteins, lipids or cholesterol-based molecules. Neurotransmitters are protein. The main difference between hormones and neurotransmitters is that Hormones are produced in the endocrine glands and released into the bloodstream where they find their movement targets at a distance from their origin. In contrast, Neurotransmitters are released into the synaptic space by a terminal of an excited presynaptic nerve cell and transmit a nerve signal to the neighboring postsynaptic nerve cell.

Explanation:

Answer:

the nervous system and endocrine system (hormones) is that the nervous system uses electrical impulses to send messages through neurons while endocrine glands use hormones to send messages to the target cells through the bloodstream.

Plants have specialized structures that perform their necessary life functions. The gases that are crucial to proper
function within a plant are oxygen and carbon dioxide. What structure would control the exchange of these gases in
a plant?

a. mesophyll
b.trichomes
c.root hairs
d.stomata

Answers

Answer:

Stomata

Explanation:

Normally stomata open when the light strikes the leaf in the morning and close during the night.

d. During photosynthesis, CO2 enters the plant leave through opened stomata and in return it releases glucose,oxygen and some little molecules of water

Plz hurry if u can. What is the momentum of a 100-kg football
player running north at a speed of 4 m/s?

Answers

the momentum is is that they’re running fast possible 50kg mark brainlest

Most mutations that cause cancer occur within body cells, and body cell mutations are not inherited. If cancer is not inherited, why does cancer statically appear to run in families?

Family members have a similar genetic make-up that may make them predisposed to cancer.
Family members are exposed to similar environmental conditions.
Family members have a widely varied genetic make-up that can be affected by specific mutagens.
Family members share the contagious mutagens that can be passed by close exposure.

Answers

Answer:

Family members have a similar genetic make-up that may make them predisposed to cancer.

Explanation:

Variation in certain genes can increase the risk of developing certain cancers. This is why certain cancers run in families. There are lots of examples where the risk factor is small, but in some cases, the risk factor is very large.

For example, mutations in BRCA1 are very highly linked to the risk of breast cancer. As a result, many women with mutations in this gene opt to get a mastectomy to reduce their chances of developing breast cancer.

Science help PLZZZ!!!

Answers

Answer: b

Explanation:

Answer: B.

Explanation: Light cannot pass through an opaque object.

Which organelle would you expect to find in animal cells but not plant cells?

O A. mitochondrion

OB. ribosome

C. lysosome

O D. A. smooth endoplasmic reticulum

Answers

Answer:

Lysosome

Explanation:

The answer is C tehe

Selena learns that, as specialized cells mature, certain organelles increase in
quantity while other organelles may disappear. She also learns that muscle cells
require large quantities of energy in the form of ATP. Based on this, she can predict
that muscle cells would contain an unusually high number of
A Lysosomes
B Ribosomes
C Rough endoplasmic reticulum
D Mitochondria

Answers

Explanation:

rewatch the video your teacher provided on edunity

Answer:

mitochondria

Explanation:

muscles need energy for contraction and lots of mitochondria is what helps them do this

As you have observed, animal hairs usually have a large medulla composed of air-filled compartments. These air-filled compartments are present for a reason and can actually help hair do its job better. Describe one reason that might explain why having a hair made of air filled compartments could be helpful to an animal.
PLEASE HELP

Answers

Answer:

to provide insulation

Explanation:

The medullary index is the proportion of the diameter of the hair medulla in regard to the diameter of the entire hair: The equation to calculate the medullary index is medulla diameter/hair diameter. In animals, the hair medulla is generally thicker compared to humans (medullary index approximately 0.5 and 0.33, respectively). The thicker the diameter of the hair medulla, the better is the insulation.

A cell without a nucleus is known as


Help thank you

Answers

Answer: prokaryotic cells

Explanation:

Answer: Prokaryotes are organisms whose cells lack a nucleus and other organelles.

Explanation:

guys can u please ASAP

1. Which of the following is provided directly by the sun to plants for photosynthesis?
A. Energy
B. Carbon dioxide
C. Oxygen

Answers

Answer:

energy is provided by the sun

A difference between food chains and food webs is that food webs are...
O bigger
Smaller

Answers

Answer: Food webs are bigger, food chain is smaller.

Explanation:

Food webs are multiple food chains into one web.

Food webs are bigger than food chains

Choose all that apply. Carbohydrates contain the following elements:

Answers

Answer: carbon, hydrogen, and oxygen

Explanation:

hydrated carbon which results to sugar and oxygen

Explanation:

plz give me brainiest

What are cat and dog paws adapted for?

Answers

Answer:

Explanation:

The cat and dog paws are adapted for walking, running, climbing and digging. Both the animals can use their front paws and back paws for different needs or just as the situation ahead of the demands.

A relationship between living things that depend on the same
resources at the same place and at the same time is called

Answers

Answer:

competition

Explanation:

i searched it up

Answer:

Competition

Explanation:

Competition is a relationship between living things that depend on the same resources. The resources may be food, water, or anything else they both need. Competition occurs whenever the two species try to get the same resources in the same place and at the same time.

PLEASE ANSWER THESE QUESTIONS COMPLETELY!!! WILL MARK BRAINLIEST!!!
DOC 1 Questions:
A. Is the suspected father actually the father of this child?
B. How do you know?

Answers

Answer:

He is not the father

Explanation:

As it says, the DNA matches up half of the time. The mother and child have 2/4 markers lined up, while the suspected father has no similar geonomes.

Which statement about water best illustrates the property of adhesion?

Answers

Answer:

The correct answer is- water droplet found on a spider web in the morning

Explanation:

Hope this helps u

Crown me as brainliest

What organelle is labeled ?

Answers

um, is there supposed to be a picture??...

Which of the following is an example of how an organism depends on Earth's natural resources for survival?
A.
Humans grow corn and wheat as food sources.
B.
Beavers use tree branches to build dams and shelters.
C.
Plants take in nutrients and groundwater from the soil.
D.
all of these

Answers

Answer: D.
Explanation: They’re all using earth’s resources.

What is produced when an atom loses an electron?

Answers

Answer:

It becomes a positively charged ion.

Explanation:

Answer:

it will lose negative charge and become positively charged

Which processes provides evidence for the claim that energy is transferred
during cellular respiration? Select all correct answers.

A. The electron transport chain

B. Carbon dioxide is released

C. hydrogen ions move down the concentration gradient across the inner membrane

D. transfer of electron carriers such as NADHand FADH2

E. water is formed

Answers

Answer:

B. Carbon dioxide is released

E. water is formed

Explanation:

Cellular respiration is defined as the metabolic processes in which chemical energy is converted into ATP and the waste product is released by the cells.

The processes that provide evidence for the claim that energy is transferred  during cellular respiration are Carbon dioxide is released and water is formed. During cellular respiration, oxygen and glucose are converted into carbon dioxide and water, and the energy is transferred to ATP.

Hence, the correct answers are "B and E".

Answer:

OPTION B&E.

Explanation:

WHEN ANYTHING UNDER GOES COMBUSTION IT RELEASES CO2.

The Pompeii worm was discovered near _______. a. a hydrothermal vent b. a sea mount c. Hawaii d. the great barrier reef Please select the best answer from the choices provided A B C D

Answers

Answer:

The answer is A. hydrothermal vent

Explanation:

I just did it

Alvinella pompejana is known as the Pompiee worm. This organims is found in the deep hydrothermal vents in the Pacific ocean. Thus, the correct option is A.

What is Pompiee worm?

Alvinella pompejana, the Pompeii worm is a species of the deep-sea polychaete worm. It is an extremophile found only at the hydrothermal vents of the Pacific Ocean, discovered in the early 1980s off the Galápagos Islands by the French marine biologists.

The Pompeii worm (Alvinella pompejana) is a deep-sea polychaete vermiform extremophile. This organism can survive at extreme conditions. It is possible because of their bacterial coating which redistributes the heat to keep the worm cool. This bacteria not only help regulate the temperature of the worm but they also break down minerals from the vent to aid their host.

Therefore, the correct option is A.

Learn more about Pompeii worm here:

https://brainly.com/question/1558377

#SPJ2

Which of the following presents the best argument as to the role of the cow in this cycle?

Answers

Answer:

Cow dung helps in balancing the environment and kills germs

Explanation:

Cow dung is used for fertility of the soil. It is also used for the control of pest in the plants. When heated cow dung can be used to cook food where there are lack of wood available. Also when it is heated it releases the gases which kills germs present in the air.

Answer:

The cow eats plants and produces carbon dioxide through cellular respiration. The plants, which gain energy from the sun, then take carbon dioxide from the atmosphere and use it in photosynthesis.

Explanation:

I did the test

How does the DNA found in your eye cells compared to the DNA found in your skin cells?

Answers

Answer:

Only 50% of the DNA in an eye cell can be found in a skin cell.

Which type of rock forms as a result of cooling and crystallization?


igneous


metamorphic


clastic


sedimentary

Answers

Igneous rocks

No need for explanation

which member of the solar system has a diameter of 3.48 x 103 kilometers

Answers

Answer:

j

Explanation:

Which of the following is not a characteristic of enzymes?
F
they are proteins
G
they act as a catalyst
H
they react with a specific substrate
they are unaffected by changes in temperature
J
they are unaffected by changes in temperature

Answers

Answer:

they are unaffected by changes in temperature. t

Explanation:

that's the answer J. u kinda wrote it in two places.

HELP PLEASE!!!!!!!!

Extend your thinking: Many chemical properties are determined by the number of valence

electrons. Elements with the same number of valence electrons will have similar properties.

Which element has similar properties to lithium? _________ Beryllium? _________

Explain: __________________________________________________________________

Answers

Same number of atoms on the outer shell, will have similar melting and boiling properties

Answer:

Same number of atoms on the outer shell, will have similar melting and boiling properties

Explanation:

just filled this out for chem


A student wondered it butterflies would show any differences in their wing color it, as caterpillars, they were grown in the dark or grown in bright white light
Which statement would be a possible hypothesis for an experiment to test this idea?

Answers

Answer:

probably bc most caterpillars are mostly green and then they turn in to like brown or other colors

Explanation:

how does an inclined plane affect the work that is done on an object?

Answers

inclined plane allows the same work to be done with a smaller force exerted over a greater distance.

Given that almost all organisms obtain energy from food by the process of cellular respiration, which is the most likely explanation for what prevents Earth from running out of oxygen?

Answers

Answer:

Oxygen cycles keeps the flow of oxygen at a constant rate.

Explanation:

The oxygen constitutes about 20% of the gaseous components in the atmosphere and it's being renewed continuously by the various microorganism and primary producers as green plants that use photosynthesis and converts the sunlight and carbon dioxide to water and releases oxygen. Oxygen cycle makes life possible as most of the elements are combined with oxygen in some way or another and are found on the lithosphere, hydrosphere, and atmosphere even biosphere hence its is present insufficient amounts.

Answer:

A.)     The net effects of the reactions of photosynthesis and cellular respiration are the opposite of one another, therefore the products of one are the reactants of the other, creating a cycle.

Explanation:  Hope this helps!!

Other Questions
Help ME anybody this is for a grade ); Fill in the missing factors to find the given estimated product582 x 23 = ______________ x ________________ = 12,000 True or false scientists that the moon was originally a comet Most of the contiguous U.S. falls between which two lines of latitude? Hint: Contiguous means touching on one or more sides Patulong naman sa business math HAHHA Which type of economy is used by the United States? HELPPPPPPPPP Determine each type of reaction. 2 C 2 H 2 ( g ) + 5 O 2 ( g ) 4 C O 2 ( g ) + 2 H 2 O ( l ) 2CX2HX2(g)+5OX2(g)4COX2(g)+2HX2O(l) Choose... N H 4 N O 3 ( s ) N 2 O ( g ) + 2 H 2 O ( l ) NHX4NOX3(s)NX2O(g)+2HX2O(l) Choose... C O ( g ) + 2 H 2 ( g ) C H 3 O H ( l ) CO(g)+2HX2(g)CHX3OH(l) Choose... 2 F e ( s ) + 6 H C l ( a q ) 2 F e C l 3 ( a q ) + 3 H 2 ( g ) 2Fe(s)+6HCl(aq)2FeClX3(aq)+3HX2(g) Choose... C a C l 2 ( a q ) + N a 2 C O 3 ( a q ) 2 N a C l ( a q ) + C a C O 3 ( s ) CaClX2(aq)+NaX2COX3(aq)2NaCl(aq)+CaCOX3(s) Choose... Lopez appealed his conviction, arguing that Congress did not have the constitutional power to pass the Gun-Free Schools Act. The government argued that the Commerce Clause, which gives Congress the power to regulate commerce with foreign nations, and among the several states, gave lawmakers appropriate constitutional power. The government said that guns in school zones led to violent crime which could affect commerce by causing insurance rates to rise and discouraging travel through unsafe areas. Contrary to the governments argument, however the power to establish and maintain schools is traditionally reserved for the states. Many states, in turn, pass this responsibility on to local governments. Although Congress has substantial experience in creating firearms legislation, it does not have knowledge about, or experience managing, any one particular school district. States also have the power to provide fire and police protection. Which expressed, concurrent and reserved powers apply to this issue? HELP!!!!!!!What is 2 8/10 + (-3.5) in decimal form is the present value of these cash flows? (Enter rounded answers as directed, but do not use rounded numbers in intermediate calculations. Round your answers to 2 decimal places (e.g., 32.16).) Present value Investment X $ Investment Y $ (b) Which of these cash flow streams has the higher present value at 5 percent? (Click to select) Requirement 2: (a) If the discount rate is 23 percent, what is the present value of these cash flows? (Enter rounded answers as directed, but do not use rounded numbers in intermediate calculations. Round your answers to 2 decimal places (e.g., 32.16).) Present value Investment X $ Investment Y $ (b) Which of these cash flow streams has the higher present value at 23 percent? According to A Quilt of a Country, how is the United States similar to a quilt? Easy 7th grade work sheet ! Please help , Ill give brainliest (all answers) Q 20.27: Liberty Bicycles currently sells unassembled bikes for $240 each. The variable production costs for each bike are $35 and the fixed production costs are $72. Liberty is thinking about selling the bikes fully assembled for $300 each. The variable costs for assembling one bike will be $18 and the fixed costs will be $31. Given these figures, Liberty will increase its net income per unit by ________ if it opts to assemble the bikes. Investiga en Internet para aprender ms sobre los artistas Remedios Varo y Manuel lvarezBravo.1. Escribe un prrafo sobre Remedios Varo, la reconocida pintora espaola-mexicana. Incluye esta informacin: a.) Qu acontecimientos artsticos y polticos sobresalen (stand out) en la vida de la artista? b.) Qu elementos le sirvieron de la inspriacin para sus obras? Descrbelos. c.) Cmo afect su vida la Segunda Guerra Munidal?2. Escribe un prrafo Manuel lvarez Bravo. Incluye esta informacin: a.) Por qu es consider ado election poets de la imagen? b.) Cules son los temas de repiten en su trabajo fotogrfico? c.) En qu momento inicia su carrera?3. Imagina que tienes la oportunidad de viajar a Mxico como fotogrfo. Qu es lugares ye gustara recorrer? En qu lugares tomaras fotos? Por qu? What is the area of the triangle? 2a-3b=4, solve for b A man with a mass of 86.5 kg stands up in a 61-kg canoe of length 4.00 m floating on water. He walks from a point 0.75 m from the back of the canoe to a point 0.75 m from the front of the canoe. Assume negligible friction between the canoe and the water. How far does the canoe move? Which of the following statements does not represent the same value as the others?the distance between 0 and 9the absolute value of negative 9the opposite of 9the absolute value of 9 can Yhu help me plzzz!!!! What landforms are created by wave erosion and deposition? Read the excerpt from "Ellis Island."For 62 years, some 12 million people passed through Ellis Island for the promise of a better life in America. They came on huge steamships, the majority from Eastern Europe and Italy, the rest from other corners of the world: Lebanon, Cyprus, China, Jamaica, and numerous other places. Many had left their homelands to escape poverty, while others had fled religious persecution or war.Which words signal the passage of time?some 12 million peoplefled religious persecutionthrough Ellis IslandFor 62 years