SOMEONE HELP PLS ILL GIVE BRAINLIEST AND 19 PT

SOMEONE HELP PLS ILL GIVE BRAINLIEST AND 19 PT

Answers

Answer 1

Sample left = 6.25 g

The percentage = 6.25%

Further explanation

Given

t1/2 = half-life = 3.8 days

t = decay time = 15.2 days

No = initial sample = 100 g

Required

Nt = final sample left

The percentage

Solution

General formulas used in decay:  

[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]

Input the value :

[tex]\tt N_t=100.\dfrac{1}{2}^{15.2/3.8}\\\\N_t=100.\dfrac{1}{2}^4\\\\N_t=6.25~g[/tex]

The percentage : Nt/No

6.25 : 100 = 6.25%


Related Questions

what is the mass in grams of a sample of 7.3 x 10^23 molecules of (iodine heptafluoride) IF7

Answers

Answer:

320 g IF₇

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Chemistry

Atomic Structure

Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:

Step 1: Define

7.3 × 10²³ molecules IF₇

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of I - 126.90 g/mol

Molar Mass of F - 19.00 g/mol

Molar Mass of IF₇ - 126.90 + 7(19.00) = 259.9 g/mol

Step 3: Convert

Set up:                               [tex]\displaystyle 7.3 \cdot 10^{23} \ molecules \ IF_7(\frac{1 \ mol \ IF_7}{6.022 \cdot 10^{23} \ molecules \ IF_7})(\frac{259.9 \ g \ IF_7}{1 \ mol \ IF_7})[/tex]Multiply/Divide:                                                                                                 [tex]\displaystyle 315.056 \ g \ IF_7[/tex]

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

315.056 g IF₇ ≈ 320 g IF₇

whats the unit for mass

Answers

Answer:

The unit for mass is the kilogram (Kg).

Explanation:

Hope this helped!! <3 good luckk!!

Answer: The unit for mass is the kilogram

The radius of a basketball hoop is 9 inches. Which expression can be used to find the
hoop's circumference in inches?

Answers

Answer:

2 [tex]\pi[/tex] r

Explanation:

Given that:

Radius of basketball  = 9inches

Unknown:

Hoop's circumference  = ?

Solution:

To solve this problem, we use the formula for the circumference of a circle.

The shape of the hoops is circular.

 Circumference of a circle = 2 [tex]\pi[/tex] r

R is the radius of the basketball hoop

If the object floats in water, is its density lower or higher?

Answers

Answer:

Its has a lower density. Think about it, a ship in the water is long because if it wasn't it would have a higher density and sink. The ship needs to diperse its weight across the water to make it less dense.

Explanation:

Your welcome! Have a great day!

4 Explain why some acids are safe to consume
while others are not.

Answers

Answer:

Household cleaners, antiseptics and battery juice are examples of toxic chemicals that you cannot consume because they have high acids concentrations. However some are very healthy such as critic acids found in oranges. :) Hope this helped.

Which of the following statements is true about the relationship between atoms and molecules? A. Most atoms are bonded together to make a molecule. B. An atom can be seen by scientists, but a molecule cannot. C. Atoms and molecules are the same and have no differences.​

Answers

Answer:

I believe the answer is A. molecules are larger than atoms so they should be visible and atoms and molecules are indeed different

To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the correct option is option A.

What is atom?

Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.

In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron.  Most atoms are bonded together to make a molecule. Molecules combine to form compounds.

Therefore, the correct option is option A.

To know more about atom, here:

https://brainly.com/question/13518322

#SPJ2

3. If 12.5 grams of copper are reacted with excess chlorine gas, then 25.4 grams of
copper (II) chloride are produced. Calculate the theoretical yield and the percent
yield. Cu + Cl2 → CuCl2

Answers

Answer:

Percent yield = 99.6%

Theoretical yield = 25.5 g

Explanation:

Given data:

Mass of copper = 12.5 g

Mass of copper(II) chloride produced = 25.4 g

Theoretical yield = ?

Percent yield = ?

Solution:

Chemical equation:

Cu + Cl₂       →        CuCl₂

Number of moles of copper:

Number of moles = mass/molar mass

Number of moles = 12.5 g / 63.5 g/mol

Number of moles = 0.19 mol

Now we will compare the moles of copper and copper chloride.

                  Cu          :           CuCl₂

                     1           :               1

                  0.19        :           0.19

Mass of CuCl₂: Theoretical yield

Mass = number of moles × molar mass

Mass = 0.19 mol × 134.45 g/mol

Mass = 25.5 g

Percent yield:

Percent yield = (actual yield / theoretical yield )×100

Percent yield  = ( 25.4 g/ 25.5 g) ×100

Percent yield = 99.6%

A piece of mental with a mass of 106 g is placed in a 50 mL graduated cylinder.The volume rises from 20 mL to 31 mL. What is the destiny of the metal?

Answers

Answer:

9.64g/mL

Explanation:

Given parameters:

Mass of the metal  = 106g

Volume of cylinder = 50mL

Volume difference  = 31mL  - 20mL  = 11mL

Unknown:

Density of the metal  = ?

Solution:

To find the density of the metal, we use;

 Density  = [tex]\frac{mass}{volume}[/tex]  

 Density  = [tex]\frac{106}{11}[/tex]   = 9.64g/mL

why do stars appear to be bigger in the night?

Answers

Answer: in the daytime the sun is out so the stars are not visible becuase the suns reflection! At night When you gaze at the constellations, every star produces an image that's the same size, but your retina isn't sensitive enough to respond to the outer parts of those images except for the brighter stars — which therefore look bigger than the fainter ones.

Explanation:

This is what I found on goog.le a while ago now it might actually help if I’m wrong I apologiz, I hope this was your quistion!

Choose the statement below that correctly describes electrons.
a. Electrons have a positive charge and are lighter than protons
b. Electrons have a positive charge and are heavier than protons
c. Electrons have a negative charge and are heavier than protons
d. Electrons have a negative charge and are lighter than protons

Answers

Answer:

d. Electrons have a negative charge and are lighter than protons

Explanation:

The best statement that describes electrons is that electrons are negatively charged and are lighter than protons.

There are three known subatomic particles which are:

Protons which are the positively charged particles within an atom. Electrons are the negatively charged particles Neutrons do not carry any charges.

The mass of the protons and neutrons are similar.

Electrons are lighter than both protons and neutrons.

What is the percent composition of nitrogen in N 2 O

Answers

Answer:

28 %

Explanation:

Mass mass N2O = 28 + 16 = 44 mass nitrogen = 2 x 14 = 28 % nitrogen Chemistry.

To be effective, a certain drug must not drop below 15 mg in the body. A 120
mgs of that drug was administered to a patient. How much time will it take for that drug to reach the 15 mg minimum level. The drug's half-life is 30 minutes.(show how you arrived at your response)

Answers

Answer:

90 Minutes

Explanation:

Original concentration = 120 mg

Half life = 30 minutes

Minimum level = 15 mg

Basically, we are to calculate the time it would take to drop from 120 mg to 15 mg.

The half life of a substance is the time it takes for the original concentration of a substance to drop to half it's starting concentration.

First Half life:

Starting concentration = 120mg

Concentration after half life = 120 / 2 = 60 mg

Second Half life;

Starting concentration = 60 mg

Concentration after half life = 60 / 2 = 30 mg

Third Half life;

Starting concentration = 30 mg

Concentration after half life = 30 / 2 = 15 mg

We have reached the minimum 15 mg level. This means it took three half lives to get there.

Total time taken = No of Half lives * Half life duration = 3 * 30 mins = 90 Minutes

What does the GOES acronym stand for?
A. Geological Open Engineering System

B. Geostationary Opertational Environmental Satellite

C. Grandma Only Eats Spagetti

Answers

Answer:

B. Geostationary Operational Environmental Satellite

Explanation:

Hope this helps!

Answer:

B

Explanation:

I’m studying it for you!

Cynthia has 200kg of magnesium. Calculate how much MgCl2 she can make.

Mg + Cl2 = MgCl2

Answers

Answer:

784.4kg

 

Explanation:

Given parameters:

Mass of Mg  = 200kg

Unknown:

Mass of MgCl₂  = ?

Solution:

  The reaction equation is given as:

            Mg  +  Cl₂ →   MgCl₂

Find the number of moles of the given specie;

  Number of moles of Mg = [tex]\frac{mass}{molar mass}[/tex]   = [tex]\frac{200000}{24.3}[/tex]   = 8230.5mole

So;

   1 mole of Mg will produce 1 mole of MgCl₂

 

   8230.5mole of Mg will produce 8230.5mole of MgCl₂

Mass of MgCl₂   = number of moles x molar mass

                    Molar mass of MgCl₂  = 24.3 + 2(35.5) = 95.3g/mol

 Mass of MgCl₂   = 8230.5mole x  95.3g/mol  = 784.4kg

 

How many electrons does H have with a -1 charge

Answers

Answer:The electron has a negative charge and the proton has a positive charge, and these charges work against each other to make the electromagnetic force that holds the entire atom together.

Explanation:

This is the answer

A 1.0 kg ball is thrown into the air and initial velocity of 30 mi./s how high into the air did the ball travel

Answers

Answer:

45.9m

Explanation:

Given parameters:

Mass of the ball  = 1kg

Initial velocity  = 30m/s

Unknown:

Height the ball will travel  = ?

Solution:

At the maximum height, the final velocity of the ball  will be 0;

  Using ;

   V²   = U²   - 2gh

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity

h is the height

     0² = 30²   - (2 x 9.8 x h)

    0 = 900 - 19.6h

      h  = 45.9m

The temperature of the system is highest when it is a
A. gas
B. liquid
C. plasma
D. solid

Answers

Answer:

gas

Explanation:

its either gas or plasma but gas should be it bc liquid and solid are cold

Metals bond with halogens to form colorless metal halides. During an experiment, chlorine water was added to a solution of potassium bromide. A record of the experiment is shown.
Experimental Record
Reactants Color of Reactants Color of Reactants after Mixing
cl,
Colorless solution
Deep yellow-orange colored solution is formed
KBT Colorless solution
Which of the following conclusions can be made about this chemical reaction based on the data? (1 point)
O Chlorine is more reactive than bromine.
Potassium bromide and chlorine do not react.
O Potassium metal is formed from a single replacement reaction.
O Bromine solution is colorless and is formed due to a single replacement reaction.

Answers

Answer:

O Chlorine is more reactive than bromine.

Explanation:

From this experiment we can conclude that chlorine is more reactive than bromine and it is the reason why the reaction is able to proceed.

The reaction is a single displacement reaction in which the position of an element in the activity series is very important. Since chlorine is more electronegative and highly reactive when compared to bromine, it will displace bromine from the solution of potassium bromide. So, we have product of potassium chloride and the bromide.

An atom contains 8 protons, 8 neutrons and 8 electrons. A second atom contains
8 protons, 10 neutrons and 10 electrons. What can be said about these two
atoms?
A. Both atoms are neutral
B. The atoms are isotopes of each other
C. Both atoms are ions
D. These atoms cannot exist in nature

Answers

Answer:

B. Isotopes mean having differing number of neutrons but having the same amount of protons basically.

Explanation:

B. The atoms are isotopes of each other

Further explanation

Given

The first atom : 8 protons, 8 neutrons and 8 electrons

The second atom : 8 protons, 10 neutrons and 10 electrons

Required

Comparison

Solution

A. Atom is said to be neutral if the number of protons and electrons is the same

The first atom neutral

The second atom - anion : charge = -2(10 electron-8 proton)

B. isotopes = the same atomic number and different mass number

The first atom : atomic number = 8, mass number = 16

The second atom neutral : atomic number = 8, mass number = 18

Both : isotopes

C. First atom = neutral, second atom anion (charge = -2)

D. Can exist in nature

Are the activities exothermic or endothermic?​

Answers

Answer:

The first 5 are exothermic reaction because heat is in product means heat is evolved or given out.

And last no reaction shows that heat is required so last reaction is endothermic reaction.

Explanation:

And heat is evolved in exothermic reaction and heat is absorbed in endo thermic reaction

Which of the following correctly shows the relationship, in terms of number of particles, of the three substances?

A. 1 mole of water < 1 mole of helium < 1 mole of aluminum

B. 1 mole of aluminum = 1 mole of helium = 1 mole of water

C. 1 mole of aluminum < 1 mole of helium < 1 mole of water

D. 1 mole of helium < 1 mole of aluminum < 1 mole of water​

Answers

The answer is b but I’m not sure

The correct option which shows the relation between particles of the three substances is 1 mole of aluminum = 1 mole of helium = 1 mole of water.

What is a particle?

A particle is a small part of matter.

The term refers to particles of all sizes, ranging from subatomic particles like electrons to visible particles like dust particles floating in sunlight.

The relationship of a number of particles of the substance can be calculated by Avogadro's law

Thus, the correct option is B. 1 mole of aluminum = 1 mole of helium = 1 mole of water

Learn more about particles

https://brainly.com/question/1685421

And this one please thank you.

Answers

Answer:

E

Explanation:

Look at bottom numbers.

90 → 88 + x

it means,

90=88+x

hence x = 2

it is also valid for top numbers.

230=226+y

y = 4

Which element below would most likely gain 3 electrons?

Answers

Answer:

Lithium

Explanation:

Radiation can travel through A. liquids B. gases C. empty space D. all of these​

Answers

Answer:

Liquids

Explanation:because animals like dolphins use sound radiation under water to hear each other

Answer:

D. all of these.

Explanation:

it can travel through solids, liquids, and gasses.

What is in the solar system?
A. All the above
B. asteroids and comets
C. The sun and everything thing that orbits around it
D. planets and their moons

PLEASE HELP

Answers

Answer:

all of the above

Explanation:

all of this is in the solar system

how many atoms are in 2.45 moles of hydrogen

Answers

Answer:

There are 1.4754246675000002e+24 atoms of Hydrogen within the measurement of 2.45 moles of hydrogen!

Explanation:

How many moles and atoms are there in 60 grams of Calcium?

Answers

Answer:

The moles present in 60 g of calcium are 1.5 moles.

Answer:

In 60 grams there are 1,5 mols

Explanation:

Please help outttt:(

Answers

Explanation:

1)

2Fe+3Cl2 →2FeCl3

2)

CH4+2O2 → CO2 +2H2O

3)

SnO2+2H2 →2H2O +Sn

4)

2KOH + H2SO4 → K2SO4+2H2O

what is one example of a electromagnetic wave

Answers

Answer:

Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Answer:

Electromagnetic waves can be split into a range of frequencies. This is known as the electromagnetic spectrum. Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Explanation:

The way Earth's rotation makes winds curve.

Answers

Answer:

it is called the prevailing westerlies

Explanation:

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