1)Fluorine-21 has a half life of approximately 5 seconds. If you start with 100g, how much
would remain after 10 seconds?
What’s the answr

Answers

Answer 1

Answer:

25 g

Explanation:

The following data were obtained from the question:

Half life (t½) = 5 s

Original amount (N₀) = 100 g

Time (t) = 10 s

Amount remaining (N) =..?

Next, we shall determine the decay constant for the disintegration. This can be obtained as follow:

Half life (t½) = 5 s

Decay constant (K) =.?

K = 0.693 / t½

K = 0.693 / 5

K = 0.1386 s¯¹

Finally, we shall determine the amount of the isotope that remained after 10 s as follow:

Original amount (N₀) = 100 g

Time (t) = 10 s

Decay (K) = 0.1386 s¯¹

Amount remaining (N) =..?

Log (N₀/N) = kt /2.303

Log (100/N) = (0.1386 × 10) / 2.303

Log (100/N) = 1.386 / 2.303

Log (100/N) = 0.6018

Take the anti log of 0.6018

100/N = antilog (0.6018)

100/N = 4

Cross multiply

100 = N × 4

Divide both side by 4

N = 100/4

N = 25 g

Therefore, the amount remaining after 10 s is 25 g


Related Questions

What is the solution to the equation below, rounded to the correct number of Significant figures? 4700 L - 281.4 L = ___ L

Answers

Answer:

46

Explanation:

Answer: 4418.6

Explanation:

Which statement describes an intensive property of matter?

Answers

Answer:

hope it helped you.

Explanation:

The properties of matter that do not depend on the size or quantity of matter in any way are referred to as an intensive property of matter. Temperatures, density, color, melting and boiling point, etc., all are intensive property as they will not change with a change in size or quantity of matter.

An intensive property is a property of matter that depends only on the type of matter in a sample and not on the amount. Other intensive properties include color, temperature, density, and solubility.

3. What noble gas would be part of the electron configuration notation for Mn?

Answers

Answer:

Argon {Ar}

Explanation:

The noble gas used for a condensed electron configuration is the one before the element which you are configuring.

In this case, the element (Mn) is manganese

The noble gas that is before this element is Argon which is the row above it

so your configuration would be {Ar} 3d^5 4s^2

What formations are created by sand deposition by waves?

Cirques
Dunes
Horns
Spits

Answers

Answer:

Spits

Explanation:

Deposit by waves include beaches. They may shift along the shoreline due to longshore drift. Other wave deposits are spits, sandbars and barrier islands

Answer: D

Explanation:

Which phrase describes neap tides?
A.) occur four times a day
B.) produce extra-low tidal ranges
C.) caused only by the pull of the moon
D.) occur at the same time as spring tides

NEED YOUR HELP.

Answers

Answer:

The answer is B

Explanation:

Neap tides are a type of to tie occuring after spring tides. It occurs when moon and sun are at the right angles to each other. It produce low tidal ranges. Hence, phrase B is correct.

What are tides ?

Tides are a geographical phenomenon taking place due to the gravitational pull by sun and moon on the ocean of earth. They are long period waves causing the ocean back and forth to the cost.

During new moons larger tides appears in earth and they are called spring tides. Spring tides occurs twice in a lunar month. During spring tides, moon appears full and earth is between sun and moon.

After seven days of spring tide, lower tides are produced when the moo and sun comes in right angle to each other. They are called the neap tides producing lower range of tidal waves . During this time moon will be half full thus for the first and last quarter of the moon. Hence, the option B neap tide produce low tidal ranges is correct.

To know more on tides, refer here:

https://brainly.com/question/9493666

#SPJ6

What is the law of conservation of matter?
A.Matter can never be changed.
B.Matter can never mix or rearrange.
C.Matter cannot be created or destroyed.
D.matter will always break down.

Answers

Considering the definition of the law of conservation of matter, the law of conservation of matter establishes that matter cannot be created or destroyed (option C).

Law of conservation of matter

The law of conservation of matter holds that, within a closed system, the amount of matter involved in a chemical reaction is constant, meaning a closed system means an environment that isolates the components involved in the reaction from the outside.

In other words, this law establishes that the mass of the reactants consumed is equal to the mass of the products obtained, even though they have been transformed into each other.

In other words, the law of conservation of matter states that matter is neither created nor destroyed during a chemical reaction, it is only transformed.

Summary

In summary, the law of conservation of matter establishes that matter cannot be created or destroyed (option C).

Learn more about the law of conservation of matter:

https://brainly.com/question/24568883

https://brainly.com/question/24783543

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. Which of these is an example of a scientific observation? *
AThe rock is smooth and gray."
BWhat is the best brand of soap?"
CMost people drive black cars."
DThe sun's light helps plants grow."

Answers

Answer:

D. The sun's light helps plants grow

Explanation:

This is a scientific observation, because it is describing the structure of a living thing.

why is soaking necessary for seed germination

Answers

Answer:

Explanation:

well it needs water like us to stay alive

a typical baseball has a mass of 350g and takes up a volume of .780L. what is the density of a baseball in g/l and g/ml?

Answers

Answer:

449 g/L

0.449 g/mL

Explanation:

Step 1: Given data

Mass of a typical baseball (m): 350 gVolume of a typical baseball (V): 0.780 L

Step 2: Calculate the density (ρ) of the baseball in g/L

The density is equal to the quotient between the mass and the volume.

ρ = m / V

ρ = 350 g / 0.780 L

ρ =449 g/L

Step 3: Convert ρ from "g/L" to "g/mL"

We will use the conversion factor 1 L = 1000 mL.

449 g/L × (1 L/1000 mL) = 0.449 g/mL

HELPPPPP plssssss!!!!!! Is the brain of the cell living or non-living?

Answers

Answer: living

Explanation: The brain of a cell is living. All parts of the cell must be alive in order for the human body to revive. The brain of a cell controls the cells, and cells are the basic block of human life.

Mass of a proton =...........

Answers

Answer:

Explanation:

A proton has a mass of approximately 938 MeV/c2, of which the rest mass of its three valence quarks contributes only about 9.4 MeV/c2; much of the remainder can be attributed to the gluons' QCBE.

Can someone explation for me ? I can’t understand.
Thanks

Answers

Answer:

2 Nitrogen

Explanation:

This is because it says Diammonium Hydrogen Phosphate. Here. (NH4)3PO4 is one way to write this. However, another way to write this is (NH4)2HPO4. There should be in fact two ammonium groups, NH4 and 1 Hydrogen to get 3+ charge to balance the 3- charge from the Phosphate.

A flashbulb of volume 1.70 mL contains O2(g) at a pressure of 2.30 atm and a temperature of 18.0°C. How many grams of O2(g)
the flashbulb contain

Answers

Answer:

0.0001637 mol

Explanation:

PV = nRT

Very important formula in chem

2.3 atm * 0.0017 L = n * 0.082057 * 291 K

= 0.0001637 mol O2

This concept is very important in chem, practice it.

The mass of an object is 13.76 g. the volume of the object is 2.83 ml. what is the density of the object to the correct number of significant figures?

Answers

Answer:

D ≈ 4.86 g/mL

Explanation:

Density = Mass over Volume

D = m/V

Step 1: Define variables

m = 13.76 g

V = 2.83 mL

D = unknown

Step 2: Substitute and Evaluate for Density

D = 13.76 g/2.83 mL

D = 4.8621908127208480565371024734982 g/mL

Step 3: Simplify

We are given 3 sig figs.

4.8621908127208480565371024734982 g/mL ≈ 4.86 g/mL

Distinguishing solutions and colloids

Which techniques would be best for separating the solute from the solvent in a solution ?

Answers

Answer:

Distillation will be the best method for the separation of solute from the solvent in a solution.

Explanation:


The human eye cannot see anything less than 40 micrometers in size. What is this length in meters?

Answers

Answer:

0.00004

Explanation:

i dont have one its just i know

WILL REWARD BRAINLIEST!!!!

Magnesium forms a __ion and wants to (gain/
lose) __electrons. Bromine forms a ___ ion and wants to (gain/lose)
electrons.

Answers

Answer:

Magnesium forms a positive ion and wants to lose electrons. Bromine forms a negative ion and wants to gain electrons.

Answer:

Magnesium forms a positive ion (Mg²+) and wants to lose two electrons.

Bromine forms a stable noble gas electronic

configuration when it gains one electron. Thus we find

magnesium as 2+ cation and bromine as a 1- anion in a

1:2 ratio in the compound .

Also, bromine forms a negative ion.

why does adding salt to ice make it melt faster

Answers

Hi :)

The salt will dissolve the ice, hence making it melt faster which lowers its freezing point below the temperature of the ice

Ice in contact with salty water therefore melts

Hope this helps :)

what is vascuoles ? ​

Answers

Answer:

Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed.

Explanation: i hoped this helped :)

Answer:

vacuole

Explanation:

a space within a cell that is empty of cytoplasm

vacuole is a membrane-bound

Electron spin around the nucleus in specific paths called?

Answers

Answer:

Electron cloud

Explanation:

it supports respiration.​

Answers

Answer:

yes yes it does

Explanation:

A student inflates a balloon with helium then places it in the freezer. The student should expect
the balloon's volume to increase
the balloon's volume to decrease
the balloon's moles to decrease
the balloon's moles to increase

Answers

Answer:

The balloon’s volume to decrease

Explanation:

According to Charles Law, when temperature decreases it tends to decrease the volume.

Why is the primary standard, KHP, used in the determination of the molar mass of an acid?

Answers

Potassium acid phthalate will serve as our primary standard. This is a large molecule (KHC8H4O4) with a molar mass of 204.2 g/mol. Instead of writing the whole formula, we abbreviate it as KHP, where "P" stands for the phthalate ion, C8H4O42-, not for phosphorus. KHP is an acidic substance, with the ionizing hydrogen being set forward in the formula for emphasis. Therefore, KHP is monoprotic and will react with NaOH in a simple 1 to 1 relationship according to the following equation:

Which is the larger atom As or P

Answers

Answer:

I think that As is larger

An empty graduated cylinder weighs 45.8772 g. After 20.0 mL of a liquid is added, the cylinder and its contents weigh 77.7572 g. What is the density of the liquid in g/mL?

Answers

Answer:

1.59g/mL

Explanation:

(777.7572 – 45.8772)g / (20.0) ml = (31.8800 g) / (20.0 ml) = 1.59 g/ml

FILL IN THE BLANKS ASAP 40 POINTS AND BRAINLIST

Answers

Answer:

1.) land

2.) water

3.) warmer

4.) rises

5.) sea

Explanation:

Hot air rises, and land heats up first.

Answer:

Here are the answers:

1.) land

2.) water

3.) warmer

4.) rises

5.) sea

Explanation:

During a day at the beach, the land heats up faster than the water. Because of this, the air over land rises over the land and the cooler, more dense air, blows into the ocean, creating a sea breeze.

In models of molecules, spheres of different colors and
sizes represent different types of atoms.
Which model shows a molecule of a substance that is made up of three
elements?

A
B
C
Or
D ?

Answers

Answer:

D

Explanation:

According to this question, each model of molecules in the options contains spheres of different colors and sizes representing different types of atoms. The atoms of the same element are the spheres of same color and size while atoms of different element are of different color or size.

Therefore, the model showing a molecule of a substance that is made up of three elements is model D because it is made up of three distinct spheres representing atoms of each element.

- The red sphere is the atom of the first element

- The big dark sphere is the atom of the second element

- The small white sphere is the atom of the third element

Answer:

D

Explanation:

How many grams of Al are needed to react with 91.8 grams of FeO
3FeO + 2Al —> 3 Fe +Al2O3

Answers

Answer:

Ans : 22.86 gm of Aluminium

Solution,

                        3FeO + 2Al ---> 3 Fe + [tex]Al_{2}O_{3}[/tex]

Given                   3          2                    

Find                    1.27       x

By the given gms of FeO find its mole and put the moles in the find,

                         

                                       [tex]n = \frac{given mass}{molecular mass}[/tex]

                  Given mass of FeO is 91.8

                   Molecular mass of FeO is 71.8

                                           

                                         n = [tex]\frac{91.8}{71.8}[/tex]  

                                         n = 1.27 moles of FeO  

Now solve for x,

                            [tex]x = \frac{2 x 1.27}{71.8}[/tex]

                             x = 0.85 moles

These are just moles of Aluminium that we need to react with FeO, so to find Grams of Aluminium we need,

                                Mass = moles x molecular mass

                                Mass = 0.85 x 27(atomic mass of Al)

                                Mass = 22.86 grams of aluminium is what we need

                                         

How many grams of F are in 225 g CaF2?

Answers

Answer:

109.575

Explanation:

TO THE F TO 225 G Caf2 iys is 1233333.9999

2. The new element Odessium (Od) was discovered in 2020 by Mr. Green. It has three isotopes: Od-284
(34.60%), Od-285 (21.20%), and Od-288 (44.20%). What is its average atomic mass?|

Answers

Answer:

Odessium (Od) has an average atomic mass of 284.45

Explanation:

Average mass is calculated from the isotopes of an element weighted by their relative abundance.

To calculate the relative average mass, you need to find the % of each isotope and use these to calculate the relative average mass

(34.60 %)/100 x 284=96.73(21.20 %)/100 x 285=60.42(44.20 %)/ 100 x 288=127.296

Add all 3 answers to get the relative average mass

96.73 + 60.42 + 127.296= 284.45
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