A sample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. A test reveals it to be 2.6 billion years old. How much
potassium-40 was in the sample originally if the half-life of potassium-40 is 1.3 billion years?
A. 4.20
B. 8.40 g
c. 12.6 g
D. 16.8 g
E. 25.2 g

Answers

Answer 1

Answer:

The correct answer is b

Explanation:

Answer 2

Answer:

Correct Answer is (B)

Explanation:

Got it right on plato Chemistry Post test

Hope I helped you out :)


Related Questions

What is a reaction rate? PLEASE HELP
a. measure of the potential energy differences in reactants and products
b. measure of the activation energy needed
c. measure of how fast products are made
d.measure of collisions between molecules

Answers

Answer:

c

Explanation:

Reaction rate, in chemistry, the speed at which a chemical reaction proceeds.if you're studying the same thing I am then that would be it

What is the speed of a car that has traveled 100 miles in 20 hours?
|

Answers

Answer:

5 mph

Explanation:

100 miles, 20 hours (divide by 2)

50 miles,    10 hours (divide by 2)

25 miles,    5 hours (divide by 2)

divide both sides by 5

5 miles,     1 hour

Answer:2

Explanation:

Which of the following is an example of a physical change in digestion?


water being absorbed in the large intestines

enzymes break down food nutrients

nutrients are broken down into different molecules

saliva breaking down carbohydrates

Answers

It should be D if it’s not I apologize dearly but I really think it’s D

Answer:

The answer would be C

Explanation:

I got it right on E D G E N U I T Y

2021

Help as fast possible I’ll mark you bbrainlist

Answers

Answer:

the farther they are the longer there cycle is. closer they are shorter time.

The gravitational pull is decreased as it gets farther from the sun and it has to go a farther distance.

A mixture consists of 28% oxygen, 14% hydrogen, and 58% nitrogen by volume. A sample of this mixture has a pressure of 4.0 atm in a 9.6 L container at 300 K temperature. This mixture is run through a gas filter, which removes the hydrogen from this system. The gas is placed back into the 9.6 L container. How many moles of gas are left in the container? A) 4.2 mol B) 2.6 mol C) 1.3 mol D) 3.9 mol

Answers

Answer:

C) 1.3 mol

Explanation:

Using gas law we can find the initial moles of the sample of the mixture, as follows:

PV = nRT

PV / RT = n

Where P is pressure: 4.0atm

V is volume: 9.6L

R is gas constant: 0.082atmL/molK

T is absolute temperature: 300K

And n are moles of the gas

PV / RT = n

4.0atm*9.6L / 0.082atmL/molK300K = n

n = 1.56moles of the mixture of the gas are present into the 9.6L container

Now, 14% of this gas is hydrogen that was removed of the system, that is:

1.56mol*14% = 0.22 moles of hydrogen are removed.

Thus, moles of gas that remains in the container are:

1.56mol - 0.22mol = 1.34mol.

Right answer is:

C) 1.3 mol

Answer:

C = 1.3

Explanation:

I just took the exam and got it right.

In sexual reproduction, a genetic mutation can ONLY be passed down to the offspring if it occurs in the sex cells.

True

False

Answers

The answer to your question is True

help me please i need help cuz its due today

Answers

A is the answer because neither has an advantage meaning the forces are equal

Answer:

I believe the answer is a. I hope this helps

what describes a property of all elements

Answers

Properties of an element are sometimes classed as either chemical or physical. ... Some properties of an element can be observed only in a collection of atoms or molecules of the element. These properties include color, density, melting point, boiling point, and thermal and electrical conductivity.

Which is a compound?
A. Orange and black shirts in a drawer
B. An alloy of copper and iron
C. Silicon and carbon in a molecule
D. A copper statue
please help, on a pex ! brainliest and an extra 50 points if right

Answers

I think b sorry if not correct

Explanation:

c Silicon and carbon in a molecule

how does eating contribute to the flow of energy in a ecosystem

Answers

Answer:

Eating contributes to the flow of an ecosystem because in a food web/chain, there is always a consumer. Starting from the very bottom of the food web/chain, all organisms eat to pass on the energy to the next cosumer. For example, a grasshopper eats some grass. That grass is made into energy. Then, a possum eats that grasshopper, the energy from the grasshopper converting to the energy of the possum. Then a giant snake comes along and eats the possum. The energy keeps flowing up and up the food chain as animals consume(and be consumed).

The food chain begins with producers, organisms such as green plants, that can make their own food. Through photosynthesis, producers convert solar energy to chemical energy, energy in the chemical bonds of the food. Plants are eaten by consumers, which are organisms that cannot make their own food.

-Carbon bonds in food are broken, which releases energy.
-Weathering breaks down rocks into chemicals like sulfur and nitrogen. -Consumers make food using light energy from the sun.
-Energy is absorbed as heat when plants make food

Intermolecular forces do not have any effect on determining the physical properties of
substances such as surface tension and melting point.
True or false

Answers

Answer:

False

Explanation:

The physical properties of melting point, boiling point, vapor pressure, evaporation, viscosity, surface tension, and solubility are related to the strength of attractive forces between molecules. These attractive forces are called Intermolecular Forces.

1. Two substances, both solids, start at the same temperature. You transfer
the same amount of energy into both solids, but substance 1 becomes a
liquid before substance 2. Which substance has a stronger molecular
attraction?
A Substance 1
B Substance 2
Please help I will give you Brainlyest

Answers

Answer:

B substance 2

Explanation:

1. Two substances, both solids, start at the same temperature. You transfer

the same amount of energy into both solids, but substance 1 becomes a

liquid before substance 2. Which substance has a stronger molecular

attraction?

A Substance 1

B Substance 2

Please help I will give you Brainlyest

Substance 2 has a stronger molecular attraction.

What are solids?

Solid is one of the four fundamental states of matter. The molecules in a solid are closely packed together and contain the least amount of kinetic energy. A solid is characterized by structural rigidity and resistance to a force applied to the surface.

Both solids are supplied with an equal amount of energy. Out of both substances, substance 2 has a stronger molecular attraction due to which it can not easily change into a liquid while substance 1 has a lesser molecular attraction so supplying of few amounts of heat will change substance 1 into a liquid state.

Hence, Substance 2 has a stronger molecular attraction.

To learn more about solids, click here:

https://brainly.com/question/14424882

Convert 48.5 grams of water to moles of water

Answers

Answer:

2.70 mol of water.

Explanation:

divide the given mass by the molar mass of water. 48.5 / 18.016g = 2.70 mol water.

Separate the following gene sequence into codons: TACGTCTTACGCTATGTC

Answer really quick plssss

Answers

Answer:

I think it's AUGCAGAAUGCGAUACAG

help help help plsss

Answers

Answer:

4.58×10^3

3.72×10^7

Explanation:

3.8×10^2 =380

+ 4.2×10^3=4200

= 4580 = 4.58×10^3

In the Periodic Table, the vertical columns that extend down the Periodic Table are called
A. periods.
B. Groups.
C: Classes
D: Rows

Answers

Answer:

b

Explanation:

What is the amplitude ?

Answers

Answer: The amplitude is a measure of the strength or intensity of the wave

Explanation: when looking at a sound wave, the amplitude will measure the loudness of the sound.

The size of an atom would be described in _______.

Answers

Answer:

atomic radius

Explanation:

so radius

Answer:

Explanation:

The average size of an atom is about 100 picometers or one ten-billionth of a meter. Almost all of the mass of an atom is in its nucleus; almost all of the volume of an atom is occupied by electrons. The number of protons (also known as its atomic number) determines the element. Varying the number of neutrons results in isotopes.

Mu Cephei is no longer considered a main sequnce star. This means it has run out of:
A:hydrogen
B:Helium
C:Oxygen
D:Iron​

Answers

Answer:

A: Hydrogen

Explanation:

Plz give me brainliest it really helps!

boron phosphite
Formula please help fast please please help me please please help

Answers

Answer: The formula for boron phosphite  is  BP

Explanation:

The answer would be BP

Hope this helped!

The bond between sodium and chlorine in the compound sodium chloride (NaCl) is a/an:

Answers

The classic case of ionic bonding, the sodium chloride molecule forms by the ionization of sodium and chlorine atoms and the attraction of the resulting ions. An atom of sodium has one 3s electron outside a closed shell, and it takes only 5.14 electron volts of energy to remove that electron.

Which element has an electron configuration that ends in the fourth energy 1 point
level? *
D
ОО
C

Answers

Answer:

here

Explanation:

which is the halogen that is in Period 5? a. iodine (I) b. strontium (Sr) ... 4. Which is a transition element with five d-block electrons in energy level 4? ... Which region contains elements with an electron configuration that ends with p3? a. A b.

Missing: point ‎| Must include: point

What do the cells do with the things they absorb

Answers

Answer:

Use them as nutrients probably

What is specific heat? How are the factors affecting it?

Answers

Answer : “Amount of heat needed to raise the temperature of 1 kg of a material by 1 c or k.”

Equation used to solve: Q=mc^T

- Change in temp
- Mass of the system
- Subtance and phase of substance

Answer:

Specific heat, ratio of the quantity of heat required to raise the temperature of a body one degree to that required to raise the temperature of an equal mass of water one degree.

Explanation:

by dividing the heat capacity by the quantity of substance in a body, the resulting specific heat capacity is a function of the structure of the substance itself. In particular, it depends on the number of degrees of freedom that are available to the particles in the substance, each of which type of freedom allows substance particles to store thermal energy.

Ples help is it Fission, Fusion, or Both 1. Incredibly high amounts of energy are released. ____ 2. Results in a nuclear change. ______ 3. The end product is heavier. _____ 4. Two nuclei become one. ____ 5. The end product is lighter. ____

Answers

Answer:

1. fission

2. both

3. fusion

4. fusion

5. fission

Explanation:

Fission refers to the splitting of a single nucleus into two or more small nuclei while fusion refers to the combination of two or more small nuclei into one heavy nucleus.

When a single heavy nucleus splits, energy is released and the end products are 2 or more lighter nuclei. On the other hand, when several light nuclei fuse into one nucleus, energy is absorbed and the end product is one heavy nucleus. Both fission and fusion result in a nuclear change.

Which two of the minerals shown have a metallic luster?

Answers

Answer:

A and D

Explanation:

Answer:

A & D

Explanation:

identify the element present in the following compound zinc chloride​

Answers

Answer:

Zinc Chloride:          ZnCl2

Molar Mass:             136.315 grams per mole

Density:                    2.907 grams per cubic centimetre

Melting Point:         563 K (290oC)

Boiling Point:          1005 K (732oC)

Explanation:

Brainliest please?

Which of the following statements is FALSE?
H2SO4 + 2 NaOH → Na2SO4 + 2 H2O is a double replacement reaction

2 KClO3 →KCl + 2 O2 is a decomposition reaction.

C6H12 + 9 O2 → 6 H2O + 6 CO2 is a single replacement reaction

CO2 + Na2O → Na2CO3 is a synthesis reaction

Answers

Answer: ITS FALSE

ExplaC6H12 + 9 O2 → 6 H2O + 6 CO2 is a single replacement reaction

nation:

What are the atoms found at the bottom of the periodic table known as?

Answers

They are called lanthanoids!

A coffee cup calorimeter contains 153.21 g of water at 22.50 °C. A 65.454 g piece of iron is heated to 101.62 °C. The piece of iron is added to the coffee cup caloriemter and the contents reach thermal equilibrium at 25.68 °C. The specific heat capacity of iron is 0.449 Jg·K and the specific heat capacity of water is 4.184 Jg·K. How much heat, , is lost by the piece of iron?

Answers

Answer:

Q = 2232J

Explanation:

In the system, the energy that is lost by the iron is:

Q = S*ΔT*m

Where Q is heat, S is specific heat of iron ΔT is change in temperature and m is mass of the piece of iron.

S = 0.449J/gK

ΔT = 101.62°C - 25.68°C = 75.94°C

m = 65.454g

Q = 0.449J/gK*75.94°C*65.454g

Q = 2232J

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