PLEASE HELP WITH THIS

Answer:

2.6 billion years

Explanation:

There are essentially two ways of solving nuclear half-life problems. One way is by applying the half-life formula, which is

A

(

t

)

=

A

0

(

t

)

⋅

(

1

2

)

t

t

1

2

, where

A

(

t

)

- the quantity that remains and has not yet decayed after a time t;

A

0

(

t

)

- the initial quantity of the substance that will decay;

t

1

2

- the half-life of the decaying quantity;

In this case, the rock contains

1/4th

of the orignal amount of potassium-40, which means

A

(

t

)

will be equal to

A

0

(

t

)

4

. Plug this into the equation above and you'll get

A

0

(

t

)

4

=

A

0

(

t

)

⋅

(

1

2

)

t

t

1

2

, or

1

4

=

(

1

2

)

t

t

1

2

This means that

t

t

1

2

=

2

, since

1

4

=

(

1

2

)

2

.

Therefore,

t

=

2

⋅

t

1

2

=

2

⋅

1.3 = 2.6 billion years

A quicker way to solve this problem is by recognizing that the initial amount of the substance you have is halved with the passing of each half-life, or

t

1

2

.

This means that you'll get

A

=

A

0

2

after the first 1.3 billion years

A

=

A

0

4

after another 1.3 billion years, or

2

⋅

1.3 billion

A

=

A

0

8

after another 1.3 billion years, or

2

⋅

(

2

⋅

1.3 billion

)

Answer:

C

Explanation:

It's pretty simple really, just find the Benefit. Pollution is definitely a harmful effect, disease is also not a benefit, and depletion of fish population is bad, so easing demand on commercial fisheries is the answer

Answer:

I can't read it. It is too small

Explanation:

It is too small for me to read

Answer:

The answer is b. seismic surveys.

Answer:

B - SEISMIC SURVEYS

Explanation:

The statement that best explains the pattern of inheritance described above is that if the two alleles of an inherited pair differ, then one determines the organism's appearance and is the dominant allele (option C).

Allele is the alternative form of the same gene occupying a given position, or locus, on a chromosome.

According to Gregor Mendel in his law of inheritance, he deduced that genes come in pairs and are inherited as distinct units, one from each parent. Mendel tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits.

Dominant alleles are alleles that are physically expressed while the recessive alleles are those that are masked by the dominant alleles.

According to this question, Mendel discovered that one parent's trait disappeared in the F1 generation of his experiment, only to reappear in one quarter (¼) of the F2 generation.

This is as a result of the concept of dominance or recessiveness in the allele encoding the particular trait. The dominant allele expressed itself over the recessive one in the F1 generation.

Learn more about inheritance at: https://brainly.com/question/4520267

#SPJ1

Answer:

Chromosomes compress, thicken, shorten, and become more apparent during prophase. At the centromere, chromosomes appear as two sister chromatids fused together. Chromosomes line up on the equator during metaphase.

provide a platform for current research on archaea, bacteria, microbial eukaryotes and viruses.

Answer:

false

Explanation:

While the Earth's rotation does play a role, it is a somewhat indirect one. The primary factor that affects the formation of winds is differences in atmospheric pressure. As is true throughout nature, any fluid will try to move from a region of high pressure to a region of low pressure.

Answer:

False

Explanation:

This is false because the earth goes one way but the wind can go all kinds of ways

Answer:

The phylum Platyhelminthes consist of three different classes: Turbellaria, Cestoda and Trematoda. Class turbellaria is composed of many free-living organisms, while some are parasitic. Trematodes are commonly known as flukes. They are parasitic flatworms with an unsegmented body.

Explanation:

The three classes of Platyhelminthes are Turbellaria, Cestoda, and Trematoda.

Flatworms are members of the Platyhelminthes phylum. The Turbellaria, popularly known as planarians, the Trematode, usually known as flukes, and the Cestoda, also known as tapeworms, are the three classes that make up the phylum Platyhelminthes. Flatworm species come in more than 25,000 different varieties.

The four classes of Platyhelminthes are Cestoda (tapeworms), which are internal parasites of many vertebrates; Trematoda (internal parasites of humans and other species); and Turbellaria (free-living marine species).

Thus, these are the differences between the three classes of platyhelminthes.

Learn more about platyhelminths, here:

https://brainly.com/question/14793366

#SPJ2

Answer:

16

Explanation:

Air pollution affects everyone equally is true statement.

When pollutants are released into the atmosphere, they endanger both human health and the health of the entire planet. The World Health Organization (WHO) estimates that air pollution causes close to seven million deaths worldwide each year.

Currently, nine out of ten people breathe air that contains more contaminants than the WHO's recommended levels, with those in low- and middle-income nations suffering the most.

The 1970-established Clean Air Act gives the U.S. Environmental Protection Agency (EPA) the power to protect public health by controlling the emissions of certain dangerous air pollutants.

Therefore, Air pollution affects everyone equally is true statement.

To learn more about Air pollution, refer to the link:

https://brainly.com/question/18951513

#SPJ7

Answer:

A.

Explanation:

The PNS consists of the nerves and ganglia outside the brain and spinal cord. 

Approximately 10 percent of the energy is passed on to the consumer and approximately 90 percent of the energy is lost as heat.

This refers to an interconnecting diagram that shows the overall food relationships between organisms in a particular environment.

90 percent of energy is usually lost as heat thereby allowing for the transfer of only 10 percent of energy to the consumers.

Read more about Food web here https://brainly.com/question/2179

Answer:

chromosomal DNA is larger than plasmid DNA

A missense mutation will change the amino acid sequence. This may alter the function of the protein, usually negatively, but sometimes positively. This later case may be favored by evolution, as the change is heritable.

ICTV announced “severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)” as the name of the new virus on 11 February 2020. This name was chosen because the virus is genetically related to the coronavirus responsible for the SARS outbreak of 2003.

Answer:

Severe Acute Respiratory Syndrome coronavirus 2  

Explanation:

 (SARS-CoV-2) was announced by International Committee on Taxonomy of Viruses as the name of the new virus on 11/02/2020. The name was chosen because the virus is genetically related to the coronavirus responsible for the SARS outbreak of 2003.Although the two viruses are related, they are different.

Answer:

zucchini

Explanation:

A balance between water withdrawn by evaporation and freshwater added by rivers and rain controls salinity. The Mediterranean Sea in Europe has a salinity of 38 parts per million or more. It's nearly cut off from the main ocean, and there's more evaporation than rain or additional freshwater from rivers.

answer :

All salts of : carbonate, CO3 2- phosphate , PO4 3- oxalate, C2O4 2- chromate, CrO4 2-sulfide, S 2- most metal hydroxides and oxides (OH-)

Exceptions :

Salts of NH4 +, and the alkali metal cations

Answer:

All salts of : carbonate - phosphate - oxalate, chromate,- most metal hydroxides and oxides

Explanation:

The only word among the available words that do not fit the pattern would be temperature.

Ash, dissolved gases, and silica content are similar in the way that all of them are made up of matter.

Matter refers to any substance with weight and is able to occupy space. Ash is made from solid particles. dissolved gases are gases, and silica contents are also from solids.

Temperature, on the other hand, is a scalar quantity. It is not something that can be held or seen. It has no weight and neither does it occupy space.

More on matter can be found here: https://brainly.com/question/4513444

Answer:

The Great Pacific garbage patch (also Pacific trash vortex) is a garbage patch, a gyre of marine debris particles, in the central North Pacific Ocean. It is located roughly from 135°W to 155°W and 35°N to 42°N.

The information provided is NOT sufficient to indicate if the TACGTGGACTGAGGACTCCTC sequence is a 'sense' strand or 'antisense' strand.

DNA is a double helix molecule composed of two long chains of nucleotides linked by hydrogen bonds.

During transcription, the sense DNA strand is actively used as template to produce a complementary RNA molecule.

In consequence, it is required to know the sequence of the resulting RNA to determine if the sequence above belongs to a 'sense' strand or 'antisense' strand.

Learn more about transcription here:

https://brainly.com/question/1048150

Answer:

C

Explanation:

Answer:

True DNA is found in both

Explanation:

Hope this helps

Answer:

This cellular respiration concept map from Byjus might help you.

Explanation:

Answer:

Explain

well just do it i belive in you dont try to act all diffrent or cool that makes people not like u just be yourself

The answer will be :

B. Heart Rate

Answer:

Classification of organisms is done while considering many factors such as:

Cell type- whether the organism is prokaryotic or eukaryotic

Cell structure- This includes both the presence and composition of the cell wall

Body type- whether the organism is multicellular or unicellular

Mode of nutrition- the method through which the organism achieves its nutritional requirement, by consuming other organisms (heterotroph) or making its own food (autotroph)

Explanation:

i beleve this is what you where asking :)

Answer:

kinetic energy

Explanation:

if something is moving that means its kinetic if its still its potential