Based on table N of the reference tables what is the number of hours required for 42k (potassium -42) to undergo three half-life periods

Answer:

Molecular formula = C₈H₁₆

Explanation:

Given data:

Percentage of hydrogen = 14.4%

Percentage of carbon = 85.6%

Molecular formula = ?

Molecular weight = 112 g/mol

Solution:

Number of gram atoms of H = 14.4/ 1.01 = 14.26

Number of gram atoms of C = 85.6/ 12 = 7.13

Atomic ratio:

            C                      :              H        

           7.13/7.13            :           14.26/7.13    

            1                      :                 2          

C : H = 1 : 2

Empirical formula is CH₂

Molecular formula:

Molecular formula = n (empirical formula)

n = molar mass of compound / empirical formula mass

n = 112 / 14

n = 8

Molecular formula = n (empirical formula)

Molecular formula = 8 (CH₂)

Molecular formula = C₈H₁₆

Answer:

46 percent of trees have been cut down.

Scienctists helps plants, but humans do destroy a lot of plants.

Scientists - helps increase plant growth.

Woodchoppers - helps decrease plant growth.

Answer:

Ba3N2

Explanation:

valency of barium is+2and nitrogen is-3.

Answer:

Explanation:

I hope this helps! :)))

Answer:

[tex]\boxed {\boxed {\sf C. \ 30 \ m/s \ east}}[/tex]

Explanation:

Velocity is the vector measurement of the change in position over time. A vector measurement means the answer must include a magnitude (numerical value) and a direction.

Here are some units of velocity:

There are many other units, but m/s is the most common.

We can eliminate choice B and D, because the units (meters-m and meters per second squared-m/s²) are not for velocity.

We are left with choice A (30 m/s) and C (30 m/s east). Remember, velocity needs a number and a direction. C contains the direction east, so it must be the correct answer.  

Answer:

For each balanced reaction, indicate the total number of atoms in the table below. Reaction. Total Number of Atoms. Reactant Side 1 Product Side. (Left).

Explanation:

Answer:  Edgy, 2020

Explanation:    <3

Answer:

refer to picture below :)

Explanation:

Answer:

Stress

Explanation:

Stress increases along faults and leads to rock breaking. Therefore option D is correct.

Along faults, stress builds up in the rocks due to the movement and interaction of tectonic plates. Stress is the force applied to the rocks, and it can occur in various forms, such as compression, tension, or shear. As the stress increases, the rocks become more strained and are pushed to their breaking point.

When the stress exceeds the strength of the rocks, they can no longer withstand the applied forces and break, resulting in an earthquake. The release of accumulated stress along the fault causes the rocks to rupture and generate seismic waves, leading to ground shaking and the propagation of energy throughout the Earth's crust.

Therefore, stress is the primary factor that increases along faults and ultimately leads to rock breaking and the occurrence of earthquakes.

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Answer:

May be 119 elements are artificially made.

Answer:

119 elements are artificially made...

Answer:

Lipid tests

Sudan III is a red fat-soluble dye that is utilized in the identification of the presence of lipids, triglycerides and lipoproteins. The Reaction: Sudan III reacts with the lipids or triglycerides to stain red in colour.

Answer:

I think soo fats and oils

Answer:

what is this question??

Answer:

a. increases

b. increases

c. decreases

Answer:

where an organism lives which includes everything that surrounds and influences the organism.

Answer:

HKOB

Explanation:

hope it helps

Answer:

unbalanced moving to the right is the awnser

Answer:

unbalanced moving to the right i think

Explanation:

Answer:

0.768 m

Explanation:

1 cm = 0.01 m

76.8 cm * 0.01 m/ 1 cm

0.768 m

Answer:

23.33%

Explanation:

from

percent yield=(mass÷total mass )×100%

Answer:

detail is given below.

Explanation:

The charged particles of nucleus are protons while neutrons are neutral having no charge.

We know that an atom consist of electrons, protons and neutrons. Neutrons and protons are present inside the nucleus while electrons are present out side the nucleus.

Electron has a negative charge and is written as e⁻. The mass of electron is 9.10938356×10⁻³¹ Kg . While mass of proton and neutron is 1.672623×10⁻²⁷Kg and 1.674929×10⁻²⁷ Kg respectively.

Symbol of proton= P⁺  

Symbol of neutron= n⁰  

The number of electron or number of protons are called atomic number while mass number of an atom is sum of protons and neutrons.

one proton contribute 1 amu to the total weight. There are 20 protons and 20 neutrons in Ca thus its atomic mass is 40 amu.

While the atomic number is 20.

Answer:

What is the name of the lab tool that is used to transfer a sample to a microscope slide?

A-a dropper

C-scissors

D-a ruler

Explanation:

got it wrong but this is the answer edg 2021

In the preparation of a microscopic slide, the items which are used are medicine dropper, scissors, and a slip cover. Thus, the correct option is D.

Microscope slides are made for the purpose of observations of different objects. After the observation, the slides are discarded. In most cases, the slides use a liquid mounting medium such as water or glycerin.

The procedure for the preparation of the slide is as follows:

1. Place a drop of liquid mounting medium in the center of the slide.

2. Position the sample on liquid with the use of tweezers.

3. At an angle, place one side of the cover slip against the microscopic slide making contact with outer edge of the liquid drop.

4. Lower the cover slip slowly, avoiding air bubbles.

5. Remove the excess water present in it with the help of paper towel.

Therefore, the correct option is D.

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Answer:

Its B) Kinetic energy increases and potential energy decreases when the velocity of an object increases.

Explanation:

because i took the test on edge 2020

Taking into account the definition of kinetic, potencial and mechanical energy, the tatement that best compares potential and kinetic energy is: Kinetic energy increases and potential energy decreases when the velocity of an object increases.

Kinetic energy is a form of energy. It is defined as the energy associated with bodies that are in motion.

Kinetic energy is defined as the amount of work necessary to accelerate a body of a given mass and at rest, until it reaches a given speed. Once this point is reached, the amount of accumulated kinetic energy will remain the same unless there is a change in speed or the body returns to its state of rest by applying a force.

The kinetic energy is represented by the following expression:

Ec= ½ mv²

Where:

Potential energy is the energy that measures the ability of a system to perform work based on its position.

Gravitational potential energy is the energy associated with the gravitational force. This will depend on the relative height of an object to some reference point, the mass, and the force of gravity as follow:

Ep= m×g×h

Where:

Finally, mechanical energy is that which a body or a system obtains as a result of the speed of its movement or its specific position, and which is capable of producing mechanical work. Then:

Potential energy + kinetic energy = total mechanical energy

The principle of conservation of mechanical energy indicates that the mechanical energy of a body remains constant when all the forces acting on it are conservative (a force is conservative when the work it does on a body depends only on the initial and final points and not the path taken to get from one to the other.)

Therefore, if the potential energy decreases, the kinetic energy will increase. In the same way, if the kinetics decreases, the potential energy will increase.

Taking into account the definition of kinetic energy, when the velocity of an object increases the kinetic energy increases.

Therefore, considering the principle of conservation of mechanical energy, the potential energy decreases.

So, the correct answer is the second option:  Kinetic energy increases and potential energy decreases when the velocity of an object increases.

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Answer:

See explanation

Explanation:

The process of electroplating an iron key with silver involves electrolysis.

The anode is a silver rod, the electrolyte is AgNO3 solution while the cathode is the iron key. A battery is connected to provide energy to drive the non-spontaneous electrochemical reaction.

Electrons flow from the anode to the cathode. Silver ions from the silver rod replenishes the silver that is deposited on the iron key in order to continue the electrolytic process.

The silver anode is therefore depleted in mass while the iron key increases in mass.

Answer:

3. P and N

Explanation:

Since they are in the same family group on the periodic table (the elements in vertical lines), they are the most similar. Hope this helps!

Answer:

3. P and N

Explanation:

Both elements are in the same group, sharing the most similar properties.

Answer:

D, all of the above

Explanation:

Answer: The main purpose of any warhead is to inflict damage on the target. The way the damage is caused may vary with different types of warheads, but in the most general sense, damage is caused by the transfer of energy from the warhead to the target. The energy is typically mechanical in nature and takes the form of a shock wave or the kinetic energy of fragments. In either case, a large amount of energy must be released. For many warheads that energy is stored in the form of chemical explosives.

Explosive Reactions

There are many chemical reactions that will release energy. These are known as exothermic reactions. If the reaction proceeds slowly, the released energy will be dissipated and there will be few noticeable effects other than an increase in temperature. On the other hand, if the reaction proceeds very rapidly, then the energy will not be dissipated. Thus, a great quantity of energy can be deposited into a relatively small volume, then manifest itself by a rapid expansion of hot gases, which in turn can create a shock wave or propel fragments outwards at high speed. Chemical explosions may be distinguished from other exothermic reactions by the extreme rapidity of their reactions. In addition to the violent release of energy, chemical explosions must provide a means to transfer the energy into mechanical work. This is accomplished by expanding product gases from the reaction. If no gases are produced, then the energy will remain in the products as heat.

Most chemical explosions involve a limited set of simple reactions, all of which involve oxidation (reaction with oxygen). A relatively easy way to balance chemical explosive equations is to assume that the following partial reactions take place to their maximum extent (meaning one of the reactants is totally consumed) and in order of precedence:

Explanation:

Answer:

10 kilograms of dynamite

Explanation:

The more volume an object has the more potential energy is available if it is the same material. 10 kilograms is larger than 5 kilograms.

Answer:

the answer is c

Explanation:

My reasoning is that its most likely

Answer:

c

Explanation:

bacteria can be a single cell and archaebacteria live in the human body

Answer:

c

Explanation:

Answer:

D

Explanation:

I'm doing USA test prep and I got it right

Answer:

Explanation:

It is D

Make the fan blades out of a lighter material.