Hree friends are talking about what they think causes shiny pennies to turn dull. Deandre says, "I think they turn dull because they're exposed to the air over time." Jamie says, "I think they turn dull because they get dirt on them from being dropped on the ground." Selina says, "I think there is dull metal inside the penny the entire time." Who do you agree with most and why?

Answers

Answer 1

Answer:

Deandre is correct.

Explanation:

When shiny pennies turn dull, due to getting rust. It gets cover with a layer of black or brown color on its surface on the exposure of air.

In this problem,

Deandre says, "I think they turn dull because they're exposed to the air over time." Jamie says, "I think they turn dull because they get dirt on them from being dropped on the ground." Selina says, "I think there is dull metal inside the penny the entire time.

Out of three friends, Deandre is correct. Shiny pennies turn dull because they're exposed to the air over time.


Related Questions

Which example describes a chemical change
taking place?
A. water turning into steam
B. sugar dissolving in warm water
C. alcohol evaporating from a food while baking
D. nails rusting while sitting outside

Answers

D . Nails rusting while sitting outside

his table shows the mass and volume of four different objects.

A two-column table with 4 rows. The first column titled objects has entries W, X, Y, Z. The second column titled Measurements has entries Mass: 16 grams Volume: 84 centimeters cubed in the first cell, Mass: 12 grams Volume: 5 centimeters cubed in the second cell, Mass: 4 grams Volume: 6 centimeters cubed in the third cell, Mass: 408 grams Volume: 216 centimeters cubed in the fourth cell.

Which ranks the objects from most to least dense?

X, Y, W, Z
X, Z, Y, W
W, Y, Z, X
Z, Y, X, W

Answers

Ranks the objects from most to least dense : X,Z,Y,W

Further explanation

Given

Object W : m=16 g, V=84 cm³

Object X : m=12 g, V= 5 cm³

Object Y : m=4 g, V= 6 cm³

Object Z : m=408 g g, V= 216 cm³

Required

Density

Solution

Density formula:  

[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]

ρ = density  

m = mass  

v = volume  

1. Object W

[tex]\tt \rho=\dfrac{16}{84}=0.19[/tex]

2. Object X

[tex]\tt \rho=\dfrac{12}{5}=2.4[/tex]

3. Object Y

[tex]\tt \rho=\dfrac{4}{6}=0.67[/tex]

4. Object Z

[tex]\tt \rho=\dfrac{408}{216}=1.89[/tex]

From most to least dense : X,Z,Y,W

How long does it take for 87.5 % of each isotope to decay?
(The isotopes are below)
Krypton-73= 27 seconds
Krypton-74= 11.5 minutes
Krypton-76= 14.8 hours
Krypton-81= 2.1 x 10^5 years

Answers

Answer:

Kr-73 = 23.625 sec

Kr-74 = 10.0625 minutes (603.75 seconds)

Kr-76 = 12.95 hours (777 minutes)

Kr-81 = 1.8375 * 10^6 years

Explanation:

What you do is multiply each of those amounts by 7/8.

27 * 7/8 = 189/8 = 23.625

23/2 * 7/8 = 161/16 = 10.0625

74/5 * 7/8 = 518/40 = 259/20 = 12.95

210000 * 7/8 = 1470000/8 = 183750 = 1.8375 * 10^6

Calculate the H+ ion concentration in a 8.8 x 10-4 M Ca(OH)2
solution.

Answers

form the molar concentration of the Ca(OH)2 which is a base we can deduct the pOH

pOH=-lg[OH-]

[OH-]=8.8 x 10-4 M

pOH=4

pH=14-pOH

pH=10

-lg[H+]=10

[H+]=10^-10

The concentration of Hydrogen ion [H⁺] in 8.8×10¯⁴ M Ca(OH)₂ is 5.68×10¯¹² M

 

The concentration of Hydrogen ion [H⁺] in a solution talks about the acidicity  the solution. Thus, we can obtain the concentration of Hydrogen ion [H⁺] in 8.8×10¯⁴ M Ca(OH)₂ solution as illustrated below:

Step 1: 

Data obtained from the question

Concentration of Ca(OH)₂ = 8.8×10¯⁴ M  

Concentration of Hydrogen ion [H⁺] =..?  

Step 2:

Determination of the concentration of Hydroxide ion [OH¯]

 Concentration of Ca(OH)₂ = 8.8×10¯⁴ M

Concentration of Hydroxide ion [OH¯] =?  

Ca(OH)₂ (aq)⇄Ca²⁺ (aq) + 2OH¯(aq)  

From the balanced equation above,  

1 mole Ca(OH)₂ produced 2 moles of OH¯.

Therefore, 8.8×10¯⁴ M Ca(OH)₂ will produce = 8.8×10¯⁴ × 2 = 1.76×10¯³ M

Thus, the Concentration of Hydroxide ion [OH¯] is 1.76×10¯³ M  

Step 3:

Determination of concentration of Hydrogen ion [H⁺].  Concentration of Hydroxide ion [OH¯] = 1.76×10¯³ M

Concentration of Hydrogen ion [H⁺] =..?    

[tex]H^{+} * OH^{-} = 1*10^{-14}\\H^{+} * 1.76^{-3} = 1*10^{-14}[/tex]

Divide both side by 1.76×10¯³  

[tex]H^{+} = \frac{1*10^{-14} }{1.76*10^{-3}}\\[/tex]

[H⁺] = 5.68×10¯¹² M  

Therefore, the concentration of Hydrogen ion [H⁺] in the solution is 5.68×10¯¹² M  

Learn more: https://brainly.com/question/17122769

How might a collision between Neptune and Halley's Comet
affect Neptune's orbit?

Answers

Answer:

It will mess up the orbit around the sun

Explanation:

The impact of Halley's Comet with Neptune may force the asteroid to descend into Neptune's orbit, which may divert somewhat from its original path.

The collision of two heavenly bodies results in a powerful impact.

This collision might prevent Halley's Comet from continuing on its path and eventually colliding with Neptune.

Learn more:

https://brainly.com/question/11453551?referrer=searchResults

23. Select the evidence that Thomson used to conclude his findings.
(a) Electrons become excited with more energy and then release that energy as atomic
spectra.
(b) Performed a series of experiments using pressure, properties of gases, and properties
of compounds.
(c) Battery Passed a cathode ray between positively and negatively charged plates and observed the cathode ray attracting to the positively charged plate.
(d) Bombarded a thin layer of gold foil with alpha particles and detected that some alpha
particles passed through the gold foil while others deflected.i

Answers

Answer:

The answer is C

Explanation:

Thomson conducted many tests with cathode rays. Which led to his discovery of the electron.

Which of the following students best describes an element?

Answers

I can’t see anything particularly. Can you repost the same question but add a picture that best represents this problem? It would really help a lot for you and myself. Anyway happy holidays and have a wonderful rest of your day.

Answer:

I dont see anything.

Explanation:

But an element is a substance that is made only out of one atom.

Questlon 7 of 10
Which object will require the greatest amount of force to change its motion?
O A. A 72 kg object moving 25 m/s
O B. A 55 kg object moving 32 m/s
OC. A 75 kg object moving 22 m/s
O D. A 63 kg object moving 27 m/s

Answers

A 72 kg object moving 25 m/s will require the greatest amount of force

Further explanation

Given

mass of object and the velocity

Required

the greatest amount of force

Solution

Newton's 2nd law :

∑F = m. a  

F = force, N  

m = mass = kg  

a = acceleration due to gravity, m / s²  

Assuming the object is moving from rest (vo = 0) and the time needed to reach its velocity is the same (delta t = equal), it can be formulated:

[tex]\tt \Sum F=m.\dfrac{v_f-v_i}{\Delta t}\\\\F=m.\dfrac{v_f}{\Delta t}[/tex]

So the force on an object depends on the product of its mass and velocity

Or if we use the impulse and momentum formula

[tex]\tt F.\Delta t=m(v_f-v_i)\\\\F,\approx m.v_f[/tex]

So that we determine which is the greatest from the multiplication of mass and velocity will produce the greatest force as well

A 72 x 25 = 1800

B. 55 x 32 =1760

C. 75 x 22 = 1650

D.63 x 27 = 1701

Option A has the greatest force

what is the average atomic mass of einsteinium? what are its common isotopes?

Answers

Answer:

Boom

Explanation:

The bomb is big and it goes boom and it also creates nuclear fragments everywhere

A compound consists of 50.04% carbon, 5.59% hydrogen, and 44.37% oxygen. What is the empirical formula of this compound?

Answers

The empirical formula of the compound is C₃H₄O₂

From the question given above, the following data were obtained:

Carbon = 50.04%

Hydrogen = 5.59%

Oxygen = 44.37%

Empirical formula = ?

Divide by their molar mass

C = 50.04 / 12 = 4.17

H = 5.59 / 1 = 5.59

O = 44.37 / 16 = 2.773

Divide by the smallest

C = 4.17 / 2.773 = 1.5

H = 5.59 / 2.773 = 2

O = 2.773 / 2.773 = 1

Multiply by 2 to express in whole number

C = 1.5 × 2 = 3

H = 2 × 2 = 4

O = 1 × 2 = 2

Therefore, the empirical formula of the compound is C₃H₄O₂

Learn more: https://brainly.com/question/15907539

Can someone solve this for me I'm confused.

Answers

Answer:

310.53 g of Cu.

Explanation:

The balanced equation for the reaction is given below:

CuSO₄ + Zn —> ZnSO₄ + Cu

Next, we shall determine the mass of CuSO₄ that reacted and the mass Cu produced from the balanced equation. This can be obtained as follow:

Molar mass of CuSO₄ = 63.5 + 32 + (16×4)

= 63.5 + 32 + 64

= 159.5 g/mol

Mass of CuSO₄ from the balanced equation = 1 × 159.5 = 159.5 g

Molar mass of Cu = 63.5 g/mol

Mass of Cu from the balanced equation = 1 × 63.5 = 63.5 g

Summary:

From the balanced equation above,

159.5 g of CuSO₄ reacted to produce 63.5 g of Cu.

Finally, we shall determine the mass of Cu produced by the reaction of 780 g of CuSO₄. This can be obtained as follow:

From the balanced equation above,

159.5 g of CuSO₄ reacted to produce 63.5 g of Cu.

Therefore, 780 g of CuSO₄ will react to produce = (780 × 63.5)/159.5 = 310.53 g of Cu.

Thus, 310.53 g of Cu were obtained from the reaction.

A scoop of potassium oxide was placed in
55g of water which produced 67g of
potassium hydroxide. What mass of
potassium oxide was used?

Answers

A scoop of potassium oxide was placed in 55g of water which produced 67g of potassium hydroxide then mass of potassium oxide was used is 12g

Potassium oxide is used widely in the agricultural industry as a fertilizer

Here given data is

Potassium oxide was placed in 55g of water which produced 67g of potassium hydroxide

We have to calculate mass of potassium oxide was used =?

Then the reaction is

K₂O + H₂O → KOH

x + 55g = 67g

x = 67g - 55g

x = 12g

Therefore mass of potassium oxide was used is 12g

Know more about potassium hydroxide

https://brainly.com/question/8906000

#SPJ1

what volume (in L) of a 3.95 M potassium chloride solution would be needed to make 325 mL of a 2.76 M solution by dilution

Answers

Explanation:

Moles of KCl in new solution = 0.325dm³ * (2.76mol/dm³) = 0.897mol.

Hence volume needed = 0.897mol / (3.95mol/dm³) = 0.227dm³ or 0.227L.

DOG SKELETAL SYSTEM BONES SKELETAL TISSUE BONE CELLS SMALLEST TO LARGEST

Answers

Answer:

tissue bone cells ,bones skeletal,dog skeletal system

Explanation:

What energy transformation occurs when a person is running

Answers

Answer:

Kinetic Energy (Hope This Helps)

Explanation:

(Brainliest)

Answer:

Chemical energy to kinetic energy. (Arguably heat energy (thermal) because of respiration)

Why do flowers have brightly-coloured petals

Answers

Answer:

Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called corolla.

How many grams are in 2.3 x 10^ -4 moles of calcium phosphate? ​

Answers

Answer:

Mass = 713.4 ×10⁻⁴ g

Explanation:

Given data:

Number of moles of calcium phosphate = 2.3×10⁻⁴ mol

Mass of calcium phosphate = ?

Solution:

Formula:

Number of moles = mass/molar mass

Molar mass of calcium phosphate is 310.18 g/mol

by putting values,

2.3×10⁻⁴ mol = mass / 310.18 g/mol

Mass = 2.3×10⁻⁴ mol × 310.18 g/mol

Mass = 713.4 ×10⁻⁴ g

Why the graph isn't just a single sloped straight line.

Answers

Answer:

the equation could have mulitplication and square roots which may change the function of the line

3. What mass of copper could be deposited from a copper(II) Sulphate solution using a current of 5.0 A over 100 seconds? ( F =96,500C,Charge of Cu in CuSO4 = +2)​

Answers

Mass of copper : 0.165 g

Further explanation

Given

5.0 A over 100 seconds

Required

Mass of copper

Solution

Faraday's law:

The mass of the substance formed at each electrode is proportional to the electric current flowing in the electrolysis

[tex]\tt W=\dfrac{e.i.t}{96500}[/tex]

e = Ar / valence = eqivalent weight

i = current

t = time

W = weight

CuSO₄ ----> Cu²⁺ + SO₄²⁻

Cu ----> Cu²⁺ + 2e

e = Ar/2

= 63,5/2 = 31,75

[tex]\tt W=\dfrac{31.75\times 5\times 100}{96500}=0.165~g[/tex]

How many grams of carbon are required to produce 0.460 moles of SiC?
SiO2 + C → SiC + CO

Answers

Answer:

Sick Core corona +iep =Qurintine

1. A group of elements that includes the most active of the nonmetals is the
a. nitrogen group.
c. noble gases.
b. alkaline earths.
d. halogens.

Answers

Answer:

D. Halogens

Explanation:

All elements in these groups have 7 valence electrons, meaning their electronegativity is the highest among the elements.

MARKING BRAINLIEST!
Many processes occur in the digestive system. Which process is best classified as a physical change?

A. digestive enzymes breaking down proteins into smaller fragments

B. teeth grinding an almond into smaller pieces in the mouth

C. bacteria converting lactose into simple sugars in the intestines

D. saliva converting the starch molecules in crackers into simpler sugars

Answers

Answer:

Teeth gridning

Explanation:

BC YOUR GRINDING IT

If the sun heated our atmosphere and the molecules began to s;read apart and rise but the atmosphere was to weak to keep them down , what would happen?

Answers

Kau rase ?!? See my level Kau sekolah x !!

Dan wants to test the effects of different amounts of antibiotic on bacteria. While setting up his experiment he makes sure to use the same type of antibiotic, the same type of bacteria, and the same type of incubator for each trial. Which phrase below best describes this part of the experiment?

Answers

Answer:

C

Explanation:

A. analyzing results

B. collecting data

C. choosing controlled variables

D. making a prediction

The correct answer would be choosing controlled variables.

The controlled variables are factors that are kept constant among the different groups of subjects during the course of an experiment so as to be able to isolate the effects of a single factor - the independent variable.

There are basically 3 types of variables in a scientific experiment;

1. The independent variable

2. The dependent variable

3. The controlled variable

The independent variables are the variables whose effects are to be determined in the course of experiments. The dependent variables are the variables that are actually measured during the course of experiments and whose values vary along with that of the independent variables. The controlled variables are other variables required for the experiment but which must be kept constant among subjects in order to be able to isolate the effects of the independent variable.

The correct option is C.

What mass of gold (Au) contains the same number of atoms as 2.61 g of aluminum (Al)?

Answers

Answer:

19.11g

Explanation:

mole = mass ÷ molar mass

mole = 2.61 ÷ 27

mole = 0.097mol

Number of atoms in 2.61g of Aluminum = 6.022 × 10^23 × 0.097

= 0.584 × 10^23

= 5.84 × 10^22atoms

To get the same number of atoms for Gold (Au), we multiply the atomic mass of Au by 0.097mol

Atomic mass of Au = 197g/mol

mass = mole × molar mass

mass = 0.097 × 197

mass = 19.109g

mass = 19.11g

38
Both ionization and dissociation produce ions of the solute in solution.
How do the two processes differ? Write two differences. *​

Answers

Answer:

Detail is given below

Explanation:

Differences:

Ionization involves the formation of ions while in dissociation substance are break into atoms, ions or molecules.

In ionization atoms and molecules gain positive or negative charge.

While in dissociation positive and negative ions are not essentially formed substance could be break into neutral small particles.

Ionization occur in covalent compounds while dissociation occur in ionic compound.

Ionization example:

Cl + e⁻    →  Cl⁻

Dissociation example:

NaCl   →   Na⁺ + Cl⁻

Here sodium and chloride ions are formed but in sodium chloride these ions were already present.

Another example:

N₂O₄   →     2NO₂

The length of a year is equivalent to the time it takes for one.. (pls help I honestly forgot )

Answers

For one complete orbit of the earth around the sun

The model below shows a part of a human body's muscular system.



Muscles are organs that make movement possible. Which organ system is responsible for controlling muscular movement?


A. Endocrine system


B. Skeletal system


C. Nervous system


D. Digestive system

Answers

Answer:

you must go to jones im doing the same test

Explanation:

Answer C. nervous system

I did the quiz

You are required to identify the following substances using their properties Substance A. conducts electricity in both solid and liquid state. Substance
B. conducts electricity in solid state but its electrical conductivity in liquid state is unknown. Also it burns at a vey high temperature to give off carbon dioxide gas.
C. conducts electricity in liquid state but not in solid state Substance
D. does not conduct electricity in any state
You have to identify that; which substance is an ionic compound, which one is covalent compound , which one is a metal and which one is graphite.​

Answers

Answer:

Explanation:

A. conducts electricity in both solid and liquid state.

   Metal

B. conducts electricity in solid state but its electrical conductivity in liquid state is unknown. Also it burns at a vey high temperature to give off carbon dioxide gas.

   Graphite

C. conducts electricity in liquid state but not in solid state

    Ionic compound

D. does not conduct electricity in any state

    Covalent compound

A metal is a substance that conducts both heat and electricity in solid and liquid state. They do this by the presence of free mobile electrons within their atomic space.

Graphite is a non - metal but it has free mobile electrons within its carbon frame work that allows of electrical conduction.

Ionic compounds are conductors only in molten state. In solid state, they do not conduct electricity and are called electrolytes in their liquid or molten form.

Covalent compounds do not ionize in solution and will not have ions which can conduct electric current.

In the ground state, all of the atoms of Period 3 elements have the same

A) atomic number
B) number of oxidation states
C) number of occupied energy shells
D) atomic mass

Answers

Answer:

C) number of occupied energy shells

Explanation:

Atomic numbers of different elements must differ, as well as atomic masses. The number of oxidation states differs per atom as well.

Other Questions
In an animal shelter, the ratio of dogs to cats is 5 to 3. There are 25 dogs. Write and solve a proportion to find the number of cats. 18 21 15 16 1.what did magnesium and oxygen atoms had to do to bond ? 2. why did the oxygen atom needed two sodium atoms to bond ? 3. why did the magnesium atom needed two fluorine atoms to bond ? please put the numbers in order so i know which answer is for the questions thanks This is an apparatus for studying the photoelectric effect. The work function of the material being investigated is 3.5 1019 J. The battery is set at 1.5 V. What is the longest wavelength of light needed to produce an electric current from the cathode (C) to the anode (A)? Que es una discusion? Cuales son las reglas de una discucion? Cuales son las pautas que debe tener una discucion? Que hace un moredador en una discucion? To find motion and distance time graph which formula we have to use please tell. june drove 116 miles and 5.8 hours at this rate how far will she drive in 5 hours A person wants to find the width of the lake by shouting and listening for the echo from the far side. If his echo returns after 2 seconds how wide is the lake? (Velocity of sound is 340 m/sec) Read the passage from The Beginnings of the Maasai.These cattle are sacred, because they are actually a divine gift from the sky god, Enkai. Our tribe makes a living by caring for the cattle, feeding them, and protecting them.What is the purpose of this passage?A.to explain the supernatural being EnkaiB.to explain where the tribe comes fromC.to explain why the culture honors cattleD.to explain how Enkai cares for the cattle what is the difference between 75.847 and 47.964? Which of the followings is a correct statement about Voir Dire in jury selection process? a. It takes much longer to conduct Voir Dire in the U. S. than other countries like Canada or England b. A few "yes or no" questions are sufficient to successfully filter out biased juror candidates c. Australia is known to have very sophisticated processes for Voir Dire d. In the U. S., it takes longer to conduct Voir Dire in civil cases than in criminal cases Write the equation in standard form. Identify the vertex, axis of symmetry, and direction of opening of the parabola. show work y = x ^ 2 + 2x + 2 Which two countries would go to war over control of the Ohio River Valley ?A: France and SpainB: France and BritainC:Britain and Spain What does Fort Mose remind us of?Question 4 options:Importance of farming for a townImportance of a northern defenseRisk people took to gain freedomRisk people took raising sheep between bat wings and bee wings what can you conclude about evolutionary relationship between these organisms? How do you know whether two quantities x and y are proportional? Why does Bolivar believe that Spains efforts to hold on to its American territories are doomed? Solve for b5/b=45/36 B= Ralph wanted to breed a pea plant that produced only purple flowers. He continued to breed purple-flowers producing pea plants together over six generations. The results of Ralph's artificial selection are shown above. What did artificial selection do the population of pea plants? Write a narrative which includes the words, 'I was so focused'. please help!!fill in the blanks with the correct form of ser or estar in present tense.