A teacher is demonstrating physical and chemical changes to her class. Which action should they use to demonstrate a chemical change?. Single choice.
(5 Points)

Cutting a piece of paper with scissors.

Ripping a piece of paper with their hands.

Burning a piece of paper with a match.

Folding a piece of paper into an airplane.

Answers

Answer 1
Burning a piece of paper with a match.



Explanation:

A chemical change is something that changes the actual make up of an object. It happens at a chemical level and can only sometimes be observable. For example cutting a paper or folding it is not changing the makeup of the paper, just the shape.

Related Questions


What is the chemical formula for the compound ammonium phosphate? Use the list of polyatomic ions and the periodic table to help you
answer.

OA. NH4H2PO4
OB. (NH4)2PO4
OC (NH)3PO4
OD. (NH4),PO4

Answers

Answer:

NH4)3PO4

this is a filler: jsjdkflflflsojsskksdnfkdod

In which of the following situations is a plant reproducing sexually?

Answers

Answer:

(ANSWER CHOICES ORDER MAY BE DIFFERENT FROM YOURS!!)

 A.  

The pollen from one flower is transported by an insect to the ovule of another flower.

 B.  

A potato plant produces a tuber, and the next year, a new plant grows from the tuber.

C.  

Part of the stem segment of a cactus plant falls off and begins to form a new plant.

D.  

A new shoot emerges from a strawberry plant and produces another plant.

Explanation:

It's "The pollen from one flower is transported by an insect to the ovule of another flower. " because i got it from study island

What will happen to the acquired energy of the ruler when you released its bent end?​

Answers

Answer:

When the Ruler is bent the energy stored in it will be potential energy, When the ruler will be released this potential energy will be then converted into the Kinetic energy as a result the ruler will move Vibrations.

The energy conservation law can be applied here

K1 + U1 = K2 + U2

K1 - initial kinetic energy

U1 - Initial potential energy

K2 - final kinetic energy

U2 - final potential energy

Energy is known commonly as the ability to do work or move a matter. The type of energy that is stored is called potential energy.

So a bent ruler often has higher energy than a flat ruler. If the ruler moves, it is having an some form of kinetic energy and thus a flying bent ruler is having higher amount of energy than the one that is not bent.

if the ruler is released at the bent end, the object or pebbles on it will fly. If you hold two positive charges near each other, they have potential energy because they will move if you release them.

If the object released is fired straight up into the air, it begins with a high kinetic energy. As it rises, it slows down due to the force of gravity pulling it toward the earth.

Due to the release, the object place on the ruler rises, its gravitational potential energy is therefore increasing and its kinetic energy is decreasing.

When the object reaches the top of its arc, it kinetic energy is zero and its potential energy is maximum.

Then gravity still to pull the object down the earth and the object will fall toward the earth and just as it falls down, its speed increases and its height decreases.

So, its kinetic energy will thus increases as it falls and its potential energy decreases.

When the object has returns to its original height, its kinetic energy will be the same as when it started upward.

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A dachshund walked 20 meters in 30 minutes. Calculate the speed. Provide your
answer in meters per hour.

Answers

40 mph becaus 30minute x2 is an hour which turns 20 into 40

A 200.0-mL sample of helium gas is in a cylinder with a movable piston at 110 kPa and 275 K. The piston is pushed in until the sample has a volume of 95.0 mL. The new temperature of the gas is 310. K. What is the new pressure of the sample? a)51.1 kPa b)261 kPa c)249 kPa d)274 kPa

Answers

Answer:

Option B. 261 KPa.

Explanation:

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

Initial volume (V1) = 200 mL

Initial pressure (P1) = 110 kPa

Initial temperature (T1) = 275 K.

Final volume (V2) = 95 mL

Final temperature (T2) = 310 K

Final pressure (P2) =?

The new pressure (P2) can be obtained by using the following formula as illustrated below:

P1V1 /T1 = P2V2 /T2

110 × 200/275 = P2 × 95/310

22000 / 275 = P2 × 95/310

80 = P2 × 95/310

Cross multiply

80 × 310 = P2 × 95

24800 = P2 × 95

Divide both side by 95

P2 = 24800/95

P2 = 261 KPa.

Thus, the new pressure of the gas is 261 KPa.

Which of the following atoms has the largest radius


F
I
Cl
Br

Answers

Answer:

francium

Explanation:

Atomic radii bary in a predictable across the periodic table.

The atomic radius elements increases down a group. Hence in the halogen group the last element in the group that is I have the largest radius.

What is atomic radius?

Atomic radius is the distance is the distance from the nucleus to the valence orbital. The atomic radius depends on the electronegativity and number of electrons in the atom.

In periodic table, atomic radius decreases from  left to right because, the electronegativity that is the ability of atomic nucleus to attracts its electron increases and thereby the atoms shrinks.

Down a group the number of shells increases and thereby electrons are more screened from the nuclear attractive pulling. Therefore in the group from fluorine, chlorine, bromine and iodine, iodine has the less electronegativity and thus largest radius.

To find more on atomic radius, refer here:

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Which on, help me please, WILL BE MARKED AS BRAINLEST

Answers

Answer:

b and c

Explanation:

Because in a chemical change in order for a substance or matter to change shape it needs to either heat up or cool down

Atoms can gain, lose, or share
electrons during a chemical change. Why
doesn't this cause the atoms identities to
change?

Answers

Answer:

Atoms can gain, lose, or share electrons during a chemical change. Chemical changes do not affect the nucleus of an atom. For this reason, an atom has the ability to retain its properties or identity even if the number of electrons is different. Therefore, the atom's identity won't change.

Explanation:

Which property can be used to tell gold and pyrite apart?
O A. Color
O B. Conductivity
C. Shininess
D. Malleability

Answers

Answer:

D. Malleability

Explanation:

Gold is made up of the element Au and it is a metal.

Pyrite is iron sulfide and it is a non-metal.

They have very similar appearance to such an extent that pyrite is widely called the fool's gold. To distinguish between the two, we simply explore their metallic properties. Gold is malleable. Pyrite is not. It will crumble under pressure.

Can you think of other solutions that might be
acidic?

Answers

Answer:

i think the answer is yess

Answer:

Limes, Lemons, Vinegar, Stomach acid, Batteries, Sour Candy, etc.

Nitric Acid, Chloric Acid, Carbonic Acid, Citric Acid, Perchloric Acid, Flouric Acid, etc.

Hope this helps!

Explanation:

If the molecules of a substanace spread out compltely to fill the entire shape of any container the substance is placed in , the substance is probly a

Answers

Answer:

Gas.

Explanation:

Matter can be found in nature in three states: solid, liquid, and gas. The main difference between these three states is the separation of its molecules.

A solid has a definite form, its molecules are closely packed together and there is little to no movement between each molecule. When put in a container, it retains its form.

A liquid does not have a definite form, its molecules can move past another and they are not as close as in a solid, but it is not as loose either. When put in a container, it takes the shape of the container but it has a defined surface.

A gas does not have a definite form, its molecules are totally free from one another and the distance that separates them is much larger than the size they have. When placed in a container, they spread out completely and fill the entire shape of the container.

Label B-L in the diagram below

Answers

Answer:

B. Polar Easterlies

C. Sub polar low

D. Prevailing westerlies

E. Sub tropical high

F. Tropical easterlies

G. Inter tropical convergence zone

H. Tropical easterlies

I. Sub tropical high

J. Prevailing westerlies

K. Sub polar low

L. Polar easterlies

Explanation:

Discuss the difference between renewable and non renewable resource and give and example of each
Will get brainliest for the best example!!!!!!!!!!!!!!!!!

Answers

Answer:

Nonrenewable energy resources, like coal, nuclear, oil, and natural gas, are available in limited supplies. ... Renewable resources are replenished naturally and over relatively short periods of time. The five major renewable energy resources are solar, wind, water (hydro), biomass, and geothermal.

Explanation:

Answer:

I am answering so the other guy can get brainliest: Renewable sources are sources that are *near-infinite (because the sun will eventually die one day) that are basically not depleted when used. Nonrenewable sources are sources that deplete when you use them, which are not easily replaceable. An example of a renewable resource is Solar Energy or Hydropower, a non-renewable source is fossil fuels or natural gas.

Explanation:


A. O CN
B. O NH4+
C. O s2-
D. O Cro 2-
Which of the following is an oxyanion?

Answers

c i think i got this off of usa test prep in class

when temperature increase gas decrease or increase support u r answer with daily life example​

Answers

Answer:

increase

Explanation:

dont known reason burr answer is correct

Answer:

When temperature increases ,gas increases ,because of the rise in temperature evaporation will take place.

Explanation:

When you boil water to make coffee/tea the kettle/boiler releases the evaporation caused by the rise in temperature.

Need help fast please I am timed and giving 47 points.
Four groups of students plan scientific investigations to answer four questions for the science fair.

Questions for Science Fair:

1-What kinds of plant life grow naturally in the town parks?

2-Which types of treats do different breeds of dogs like best?

3-Do different types of grass affect how far a ball rolls?

4-How are the chemicals in different vegetables similar?

Which question would most likely be answered with an experimental investigation?

A-1
B-2
C-2
D-4

Answers

Answer:

C

Explanation:

Answer:

C - 3

Explanation:

This can be actually tested

I just need to know which ones are insulators and the others conductors

Answers

Answer:

below

Explanation:

Insulators: wood, tire, glass cup, wool hat

Conductors: frying pan, penny, wire

What is the total number of electrons in As-3?

Answers

Answer:

Arsenic, As, has atomic number 33, which is the number of protons in the nuclei of its atoms. A neutral As atom would also have 33 electrons. The electron configuration of a neutral arsenic atom is [Ar]3d104s24p3

Explanation:

which of the nonmetals is the least reactive?

a) Ne

b) O

c) Cl

d) F

Answers

Flourine

Explanation:

The element F has a high negative (ΔeqHө) but not so high IE1 . Therefore, it is the least reactive non-metal.

I’m sure it is d)F hope that helps :>

YALL can you please answer this

Write a balanced chemical equation for the reaction that occurs when calcium metal undergoes a combination reaction with O2(g).

Answers

Answer:

CaO[tex]_{s}[/tex]

Explanation:

 The chemical reactants are;

            Calcium metal = Ca[tex]_{s}[/tex]

             Oxygen gas  = O₂[tex]_{g}[/tex]  

 Now let us write the reaction:

     2Ca[tex]_{s}[/tex]   +  O₂[tex]_{g}[/tex]  →  2CaO[tex]_{s}[/tex]

The product is CaO in solid form.

This reaction is a combination or synthesis reaction in which two substances combine to give a single product.

n the Bohr model of an atom (shown), protons are represented in blue, the neutrons are red and the electrons are green. Use your periodic table and determine which of the following atoms is represented by the Bohr model.

Answers

Answer: B

Explanation: Valence electrons are the number of electrons out the outermost shell of the diagram. In this diagram, there is one valence electron. This means that it is highly reactive since the shell is not complete and needs other elements to be able to complete the outermost shell. If this model had a full outermost shell, then it would not be reactive (noble gases).

Answer: B

Explanation:This test it anoying.

UCI Chemistry researchers, Prof. F. Sherwood Rowland and Dr. Mario Molina werefirst to discovered in 1973 that chlorofluorocarbons (CFCs) were depleting the Earth’sozone layer when released into the atmosphere. Once they reach the stratosphere, Clis released from the CFCs molecules by interaction with UV light. Free Cl atoms areable to react with ozone in a catalytic cycle that converts O3into the more stable O2.It is estimated that a single Cl atom is able to react with∼100000 O3molecules.Although CFCs production was banned in 1996, there are still a substantial numberof motor vehicle air conditioners (MVACs) that use CFC-12 (CF2Cl2) as refrigerant.The average CFC-12 emission rate from operating MVACs has been estimated tobe 59.5 mg per hour per vehicle (Zhang et al.Environ. Sci. Technol. Lett.2017).How much chlorine, in kg, is added to the atmosphere in a year due to 100 millionMVACs using CFC-12 as refrigerant?

Answers

Answer:

15.27895 x 10⁶kg of chlorine radical is added to the atmosphere in a year due to 100 million MVACs                                                                                              

Explanation:

Chlorofluorocarbons (CF₂Cl₂) from refrigerants produce chlorine radicals according to the following equation

         CF₂Cl₂ → CF2Cl  + Cl ⁻ .........(1)

From equation 1, one mole of CF₂Cl₂ produces one mole of Chlorine radical

From the question,

The emission rate of CF₂Cl₂ is 59.5mg/hour/MVAC

In one day the emission rate would be 59.5 x 24hours

                                                                  = 1428mg/day

In one year, the emission rate would be 1428mg/day x 365days

                                                                 =  521220mg/year

                                                                   = 521.220g/year/MVAC

Therefore the emission rate for 100 million MVAC using CF₂CL₂ in a year is

                                                                    = 52122 x 10⁶g/year/MVAC

                                                                    = 52122 x 10³kg/year/MVAC

The molar mass of CF₂CL₂                       = 120.913g/mol

No of moles  of CF₂CL₂                              = mass/ molar mass

                                                                     = 52122 x 10⁶g / 120.913g/mol

                                                                      = 431 x 10⁶ moles of CF₂Cl₂

From equation 1,  since one mole of CF₂Cl₂ produces one mole of Chlorine radical, it implies that

431 x 10⁶ moles of CF₂Cl₂ would produce 431 x 10⁶ moles of chlorine radical,

Therefore, to find the mass of chlorine radical produced, we use the formula

No of moles of chlorine radical  = mass/ molar mass

431 x10⁶ moles = mass of chlorine radical /molar mass of chlorine radical

431 x 10⁶ moles = mass/ 35.45g/mol

mass of chlorine =  431 x 10⁶ moles x 35.45 g/mol

                            =    15278.95 x 10⁶ g

In Kg, the mass    =   15,278.95 x 10³kg of cholrine radical

                             =   15.27895 x 10⁶ Kg of chlorine radical

                                                                                                 

What causes uneven heating on Earth? *
Temperature Differences
Earth's Rotation
Earth's Revolution
Global Wind System
if u get it right i will give brainliest

Answers

Answer:

temperature differences

Explanation:

Solar heating of the Earth's surface is uneven because land heats faster than water, and this causes air to warm, expand and rise over land while it cools and sinks over the cooler water surfaces. ... Wind is the result of pressure changes in the atmosphere.

Almost all of Earth's atmosphere is created through the process of photosynthesis.

True

False

Answers

Answer:

False

Explanation:

This chemical equation represents a chemical reaction.
NaCN + HBr + NaBr + HCN
Which two chemicals are reactants in the chemical reaction?
A.NaCN
B.NaBr
C.HCN
D.HBr

Answers

Answer: NaCN and HBr

Explanation:

5. A family is traveling using three different modes of transportation. Seven of them travel in a large recreational vehicle, two in a car, and one on a motorbike. They start from the same place, travel at the same speed, and reach the final destination at the same time. *

Answers

Answer:

All three vehicles have the same kinetic energy because they have equal speed.

The outer shell of this element was determined as illustrated here.

It must be a _____.

Answers

The answer is ((Oxygen,O)) on the periodic table it’s number is 8. Which is the number of dots around the nucleus.

Which scientist is known for developing the planetary model of the atom

Answers

Answer:

Ernest Rutherford

Explanation:

The Rutherford model, proposed originally in 1911, dipicts a planetary model of the atom in which there is a nucleus and electrons circling it.

Answer:

Niels Bohr

Explanation:

Why is the wavelength of 633 nm used to analyze the standard solutions and drink samples?

Answers

Answer:

Corresponding with orange light, is the wavelength that blue solutions absorb the most.

Explanation:

If light is diffused through a solution of a given color, emerges of light from another wavelength is consumed and fades away. However, the wavelength of light relating to the color of such a solution is transferred. The color of the light is consumed is usually the contrasting one being transferred. As seen in a color wheel where, blue complement orange, red complement green, and yellow complement violet.

Thus, for a blue substance in solution, its complementary color is said to be orange, Given that the wavelength of orange color varies from 600 - 640 nm where it's maximum absorbance is approximately 633 nm. This wavelength is what is employed when analyzing the standard solutions and drink samples.

What forces are present in this situation?
An elevator is rising at a constant speed; the elevator is the object in this situation.
A.gravity and tension
B.normal,gravity,and tension
C.normal and tension
D.gravity

Answers

Answer:

A. Gravity and Tension

Explanation:

Gravity and Tension would be the only things changing the rising speed of the elevator.

Normal makes no sense not sure why that is an answer.

Gravity effects how much Tension is pulling on the elevator to go down while the elevator is pushing up.

Let me know if you have any other questions.

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can someone help me Solve the system. 3x - 2y = 12 and 3x - 3y = -2 Which statement best describes a population with a growth rate of 0.25?The population is decreasing exponentially.The population is increasing by 0.25 new individuals per existing individual each year.The population is decreasing by 0.25 individuals per existing individual each year.The population is growing exponentially. A prescription is presented to you as follows: Diabinese 250mg qid for an 85 year old person weighing 120 pounds. Would you fill the prescrition written? I. Fill in the blanks in the following sentences with the appropriate Spanish vocabulary word(s). Note the hints in parentheses.2. Before you take a test, you should .3. A Juan y a Marta gusta bailar.5. En mi libre, me gusta jugar al ftbol.6. Claro que ! means "of course!"7. The opposite of sin is .8. La profesora est (in front of) la pizarra.9. Yo (always) bail en las fiestas.10. Yo no bailo bien. Yo bailo .II. Answer the following questions with complete sentences in Spanish. Note the hints in parentheses.1. Te gusta bailar?2. Dnde est el libro? (under the desk)3. A la profesora, le gustan las enchiladas?4. Dnde ests? (next to the cafeteria)5. Te gustan las pelculas romnticas?6. How would you translate the sentence "Spanish class is very far away"?7. Cules son tus pasatiempos favoritos? (to read, to play soccer, and to dance)8. Tell someone what you like to do. (to sing OR to play the piano)9. A ustedes, les gusta la clase de arte? (s)10. Tell someone that the pencil is on top of the book. Jacob made 12 out of 36 shots he attempted during a basketball game.What percent of shots did he make? Compare and contrast the applications and benefits of circle graphs and bar charts What is the meaning of this metaphor: Our close resemblance turned the tide/ Of my domestic lifeA)Looking alike made their lives horrible.B)Since they looked alike, their lives took a new course.C)They moved the ocean because they looked alike.please help i have 50 mintues to finish this and please be sure youre right have the points and ill give braniest if you get it right ty HELP ME ASAP PLEASE.Based on your analysis of this article, answer the following questions: Which argument seemed more persuasive? What language choices made the argument persuasive? Your answer should be 3-5 sentences long."School gardens are popping up in school yards across the nation. While some view these gardens as hands-on learning opportunities, others view the gardens as taking time away from classroom academics. Opponents to school gardens say that students need rigorous classroom teaching in order to be successful adults. Gardening is something adults typically do in their free time as a hobby, not as work. Those against school gardens say that schools should not teach a hobby during work hours. Finally, opponents say that research does not provide any proof that time spent in a schools garden leads to higher graduation rates.Supporters of school gardens say that these gardens allow students to apply what they are learning in class to the real world. Students have to problem solve, and work together. Students apply the skills they are learning in science and math in the garden. No other experience can provide a natural laboratory for students to explore living things and the environment. Nearly every research study for the past 100 years has shown that for students to perform well after graduation, schools must teach to the whole child and provide whole-school experiences." Mr. Lopez wrote the equation 32 g + 8 g minus 10 g = 150 on the board. Four students explained how to solve for g.Alyssa: I added 32 and 8 to get 40, subtracted 10 to get 30, and then subtracted 30 from 150 to find the value of g, which is 120.Rahul: I added 32, 8, and 10 to get 50, and then I subtracted 150 to find the value of g, which is 100.Toni: I subtracted 18 from 32 to get 14, which I then divided into 150 to find the value of g, which is 10 and StartFraction 5 Over 7 EndFraction.Wilhem: I added 32 and 8 to get 40, subtracted 10 to get 30, and then divided both sides by 30 to find the value of g, which is 5. Which students work is correct?AlyssaRahulToniWilhemMark this and return Save and Exit Next Hello help 4 brainliest answer! How does a magnetic field cause electric charges to form an electric current? O A. A force is exerted by the magnetic field on only the positive charges in the wire. B. 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What is the probability a randomly selected pet from the store is female or a puppy? pls help me if you can i need help with this please need all of these answered asap When a law is passed it MUST be passed by both houses in Congress. * So, what is actually produced during the light reaction? Do you know the chemicalequation? What is in the center of our galaxy? - The Sun- A larger star (than the Sun)- An asteroid field- A supermassive black hole