Which of the following is an example of a chemical change?


A. Boiling water
B. Burning paper
C. Dissolving sugar in water
D. Melting gold​

Answers

Answer 1

Answer:

b.) burning paper

Explanation:


Related Questions

Newton wrote the mathematical concepts to prove the _____ shape of planet’s orbits.
spherical
circular
triangular
elliptical

Answers

Answer:

Eliptical

Explanation:

While some orbits may seem circular, like Earth's, it is still an ellipse. Planets orbit stars in an elliptical shape, but some come very close to perfect circles. As for the other two, im certain you have never seen a triangular or spherical orbit. Hope this helps.

Balance the Chemical Equations

Rb + RbNO3---> Rb2O + N2

please help me

Answers

Answer:

10Rb° + 2RbNO₃  =>  6Rb₂O + N₂

Explanation:

Given:   Rb° + RbNO₃ => Rb₂O + N₂

=> 1st balance rubidium in RbNO₃ against Rb₂O  by inserting a '2' coefficient before RbNO₃ and a '6' coefficient  before Rb₂O

=> Rb° + 2RbNO₃  =>  6Rb₂O + N₂   => Oxygen and Nitrogen are balanced. All that remains is balancing Rb by inserting a '10' coefficient.

=>  10Rb° + 2RbNO₃  =>  6Rb₂O + N₂

Note: In balancing chemical equations, saving an element that is not part of a compound until last frequently gives balance by inspecting the number of elements of the specific kind and boosting its coefficient to balance the equation.  

Balanced equation =>  10Rb° + 2RbNO₃  =>  6Rb₂O + N₂

The balanced chemical reaction can be of the equation given is [tex]2Rb + RbNO_3 - > Rb_2O + N_2[/tex].

We need to make sure that the amount of atoms of each element is the same on both sides of the equation in order to balance the chemical equation [tex]Rb + RbNO_3- > Rb_2O + N_2[/tex].

By counting the atoms in each element, we may begin to balance the equation. We have one Rb, one Rb, one N, and three O atoms on the left side. We have two Rb, one N, and two O atoms on the right side.

We can add a coefficient of 2 in front of [tex]RbNO_3[/tex] to balance the Rb atoms, which gives us:

[tex]2Rb + RbNO_3 - > Rb_2O + N_2[/tex]

Thus, now, the equation is balanced with two Rb atoms on both sides.

For more details regarding chemical reaction, visit:

https://brainly.com/question/34137415

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Now you will focus on a second hypothesis. This hypothesis can be very similar to the first, but this time you want to focus only on the second variable in question, speed. What could be a hypothesis that would illustrate the relationship between speed and kinetic energy? Use the format of "if…then…because…” when writing your hypothesis.

Answers

Answer:

If the mass of an object increases, then its kinetic energy will increase proportionally because mass and kinetic energy have a linear relationship when graphed.

Explanation:

is correct answer

Answer:

Sample Response: If the speed of an object increases, then its kinetic energy will increase proportionally because speed and kinetic energy have a linear relationship when graphed.

Explanation:

Can someone help me with these two questions

Answers

4. The pressure of the inner core is higher than the outer core

5. The coolest layers are farthest from the core

Balance the following chemical equation by providing the correct coefficients.

Na + H2O ———— NaOH+H2
Please help!!!!!!!!

Answers

Answer:

2, 2, 2, and 1

Explanation:

I put that in and it was correct.

1pt Twins raised in different families still exhibit similar mannerisms, indicating that at least some behavior is
O A. genetis
OB. environmental
O C. instinctual
OD. learned

Answers

The answer is A, genetic.


Twins reared apart help identify genetic and environmental influences on behavioral development, this allowed direct estimates of genetic effects on behavior and health, because they share all their genes, but differ in their environments.

I will need help plz thank you

The Earth's surface is _____ water.

50 %

71 %

97 %

Answers

Answer:

71%

Explanation:

71% explanation: About 71 percent of the Earth's surface is water-covered, and the oceans hold about 96.5 percent of all Earth's water. Water also exists in the air as water vapor, in rivers and lakes, in icecaps and glaciers, in the ground as soil moisture and in aquifers, and even in you and your dog. Water is never sitting still.

The article states that amplitude plays a role in what happens to a sound
wave. Why do you think higher amplitude waves are more often
transmitted while lower amplitude waves are reflected or absorbed?

Answers

Answer:

Sound waves travel through matter

Explanation:

Higher amplitude sound waves are more likely to be transmitted through matter instead of reflected. Lower amplitude sound waves are more likely to be reflected or absorbed, resulting in a lack of an echo. Sound can travel through air, water, and solids

The level of CO2 in the blood is detected by chemoreceptors located in the aortic arch
and carotid arteries. These send impulses to either the cardioaccelerator or
cardioinhibitor center in the hypothalamus of the brain, which in turn sends an
impulse to the pacemaker of the heart to increase or decrease heart rate. Draw a
feedback diagram to illustrate what happens to restore homeostasis when blood CO2
rises.

Answers

Answer:

The level of CO2 in the blood is detected by chemoreceptors located in the aortic arch

and carotid arteries. These send impulses to either the cardioaccelerator or

cardioinhibitor center in the hypothalamus of the brain, which in turn sends an

impulse to the pacemaker of the heart to increase or decrease heart rate. Draw a

feedback diagram to illustrate what happens to restore homeostasis when blood CO2

rises.

Explanation:

The level of CO2 in the blood is detected by chemoreceptors located in the aortic arch

and carotid arteries. These send impulses to either the cardioaccelerator or

cardioinhibitor center in the hypothalamus of the brain, which in turn sends an

impulse to the pacemaker of the heart to increase or decrease heart rate. Draw a

feedback diagram to illustrate what happens to restore homeostasis when blood CO2

rises.

A model that describes the formation, ______________, and reformation of rocks.

Answers

the answer is probably deformation
i believe it’s deformation too tho it makes a lot of sense im sorry if im wrong!

How many atoms of beryllium are equal to 0.39 moles of beryllium?

Answers

Answer:

2.35 x 10²³atoms

Explanation:

Given parameters:

Number of moles of Be  = 0.39moles

Unknown:

Number of atoms  = ?

Solution:

To solve this problem:

                1 mole of a substance contains 6.02 x 10²³ atoms

               0.39 mole of Be will contain 0.39 x 6.02 x 10²³ = 2.35 x 10²³atoms

Which equation is balanced in an acidic solution?

Answers

Answer:

I think C but it could be D

Explanation:

I would say go for C

How many grams are in 2x10^24 formula Units of CaCO3

Answers

Answer:

332g

Explanation:

Given parameters:

Formula units  = 2 x 10²⁴

Unknown:

Mass of the compound = ?

Solution:

The formula of the compound is:

            CaCO₃

      6.02 x 10²³ atoms are contained in 1 mole of a compound

       2 x 10²⁴ atoms will be made up of [tex]\frac{2 x 10^{24} }{6.02 x 10^{23} }[/tex]   = 3.32mole of CaCO₃

 Mass of CaCO₃  = number of moles x molar mass

      Molar mass of CaCO₃  = 40 + 12 + 3(16) = 100g/mol

 Mass of CaCO₃  = 3.32 x 100  = 332g

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.

Give a real-world example of an energy transformation that uses two of the following forms of energy: chemical, mechanical, nuclear, gravitational, radiant, electrical, thermal (heat), and/or sound.

Answers

Answer:

Chemical Energy is energy stored in the bonds of atoms and molecules. Batteries, biomass, petroleum, natural gas, and coal are examples of stored chemical energy. Chemical energy is converted to thermal energy when we burn wood in a fireplace or burn gasoline in a car's engine.

MARK BRAINLIST PLZ NEEDS ONE MORE

Explanation:

concept of mole chemistry question



Answers

Answer:

How many molecules of water are there in 54 g of H2O H 2 O ? Solution. Molar Mass of H2O H 2 O = 2 + 16 = 18 g/moles. So ,number of moles of H2O H 2 O = Mass/Molar Mass = 54/18 =3 moles. Now 1 moles = 6.022×1023 6.022 × 10 23 molecule.

If we react 5.4g of sodium chloride with an unknown amount of fluorine gas, we produce 4.9g of sodium fluoride and 3.7g chlorine gas. How much fluorine was consumed in the reaction?

Answers

Answer:

4.43 g

Explanation:

The reaction between sodium chloride and flourine gas is given as;

NaCl + F2 --> NaF + Cl2

From the stochiometry of the equation;

1 mol of NaCl reacts eith 1 mol of F2 to form 1 mol of NaF and Cl2

Mass of 1 mol of F2 = 38g

Mass of 1 mol of sodium flouride, NaF = 42g

This means 38g of flourine reacted with NaCl to form 42g of NaF

xg of F2 would form 4.9g of NaF

38 = 42

x = 4.9

x = 4.9 * 38 / 42

x = 4.43 g

The diagram below shows the apparatus used to pass a current through copper
sulfate solution.
1 x
Positive electrode
Negative electrode
Copper sulfate solution
What is the name of component X in the diagram above?
point
Fuse
Switch
оооо
Ammeter
O Battery

Answers

i think the answer is b) i.e. Switch....

according to me ammeter and battery are already there...

How can calcium oxide change directly to limewater?
Wants equation and observation

Answers

Answer:

Lime(Calcium Oxide) is a white solid with strongly basic properties.Lime reacts readily with water to produce slaked lime,which is the chemical compound calcium hydroxide.....

When carbon dioxide gas is passed through or over limewater,it turns milky due to the formation of calcium carbonate.

Bohr's model of the atom attempts to explain the idea that
the atom is mostly empty space
O all atoms of one type of element are identical
O energy is quantized
O protons and neutrons are found in the nucleus

Answers

Answer:

O energy is quantized

Explanation:

Bohr's model of that atom attempts to explain the idea that energy is quantized within an atomic space.

In 1913 Neils Bohr put forward his own model of the atom based on the quantum mechanics developed by Planck. He suggested that the extranuclear part consists of electrons in specific spherical orbits around the nucleus. As one moves outwards from the nucleus the energy level increases.

All changes saved
A gas is at 275 K, and its temperature is raised to 400 K. The volume is measured at 5.82 L after the gas is heated. What is
the volume of the gas before it is heated?
8.25 L
12.0L
2.00 L
4.00 L

Answers

Answer:

4.00L

Explanation:

Using Charle's law, which have the following equation:

V1/T1 = V2/T2

Where;

V1 = initial volume (litres)

T1 = initial temperature (Kelvin)

V2 = final volume (litres)

T2 = final temperature (Kelvin)

According to the information provided, T1 = 275K, T2 = 400K, V1 = ?, V2 = 5.82L

Hence, using the formula;

V1/275 = 5.82/400

400 × V1 = 275 × 5.82

400V1 = 1600.5

V1 = 1600.5 ÷ 400

V1 = 4.001

Therefore, volume of the gas before it is heated is 4.00L

A closed container is the best way to measure the volume of a
A. gas
B. liquid
C. solid
D. Both A and B are correct.

Answers

Answer:

A closed container is the best way to measure the volume of a liquid

Please help
I will give a brainliest

Answers

THe correct answer is heat

Answer:

hi

Explanation:

heat

A student claims that a large percentage of water on Earth is immediately available to drink. Is he correct? Why or why not?

Answers

Answer:

No, the student is not correct. The earth may have a lot of water... but not every part of water is drinkable. Most water is filled with bacteria and or viruses making it not suitable to drink! :)

Explanation:

HOPE THIS HELPS! BRAINLIEST? :)

What does the salinity of seawater represent?

The concentration of salt dissolve in the ocean
The concentration of all dissolved chemicals in the ocean
The volume of salt in the ocean
the mass of salt in the ocean

Answers

Answer:

Salinity is a measure of the 'saltiness' of seawater, or more precisely the amount of dissolved matter within seawater.

NaOH+HCL=NaCL+H2O

what is the total number of grams of h2o produced when 116 grams of the product NaCL is formed from 80 grams of NaOH and 72 grams of HCL?

A)9.0. B)18.o. C)36.0 D54g

Answers

The answer is c36.0 I hope it’s right

A vector is a quantity with magnitude and ____

Answers

A direction . A vector quantity.

Answer:

direction

Explanation:

A P E X

How many valence electrons must Calcium lose when forming an ionic compound with Bromine?

Answers

Answer:

2

Explanation:

Please help quick
1) How much heat does 23.0 g of water absorb as its temperature increases from 25.4 °C to 42.8 °C?

2) A sample of unknown metal has a mass of 120.7 g. As the sample cools from 90.5 °C to 25.7 °C, it releases 7020 J of energy. What is the specific heat of the sample?

Answers

Answer:

c = 0.898 J/g.°C

Explanation:

1) Given data:

Mass of water = 23.0 g

Initial temperature = 25.4°C

Final temperature = 42.8° C

Heat absorbed = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Specific heat capacity of water is 4.18 J/g°C

ΔT = 42.8°C - 25.4°C

ΔT = 17.4°C

Q = 23.0 g ×  × 4.18 J/g°C × 17.4°C

Q = 1672.84 j

2) Given data:

Mass of metal = 120.7 g

Initial temperature = 90.5°C

Final temperature = 25.7 ° C

Heat released = 7020 J

Specific heat capacity of metal = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 25.7°C - 90.5°C

ΔT = -64.8°C

7020 J = 120.7 g ×  c ×  -64.8°C

7020 J = -7821.36 g.°C ×  c

c = 7020 J / -7821.36 g.°C

c = 0.898 J/g.°C

Negative sign shows heat is released.

1. What happens when an electric current is applied to a tube filled with a gas, like neon, electrons...

Answers

It goes boom I think

Answer:

When an electric current is passed through a gas, the gas emits light. Neon signs operate in this way; a tube having an electrode at each end is filled with a gas at low pressure and a high voltage (generally in the range of 1000 to 5000 volts) is applied to the electrodes.

Explanation:

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Objects in the universe vary in their composition. Which of the following best describes the composition of a galaxy?A. A solar system containing more than one star larger than our sunB. A collection of asteroids, dust, and gases orbiting each other in spaceC. An unidentified object in space that can be seen using a powerful telescopeD. A collection of billions of stars and their satellites held together by gravity 9x+ 5 = 14x 4I need help with this I have to solve for x PLS HELP! ITS DUE SOON ILL GIVE BRAINLIEST People and blank careers are per suitors they like leader ship pools as well as sales they often have a good verbal abilities and talk to people into doing things their way Write a sentence using a nouns that name two or more cities or states you would like to visit causes of multilingualism ________is our perception ofone personality trait influences howwe view a persons entire personality.Select one:a. Perceptionb. Individual Personalityc. Stereotypingd. Halo effect= Halo effect Which part of the South American continent is suitable for thepractice of agriculture? Why? Use the word Shinto in a sentence. The Periodic Table Question 4 of 10 If an element forms a 2+ ion, in which group of the periodic table would you expect to find it? D A. 2 B. 17 O C. 1 D. 18 7 a rectangle has a perimeter of 14 ft write whole-number dimensions for another rectangle with the same perimeter. This is circle theorems I am not rly good at this Can someone please explain how to do number 9. The hydrophobic effect is related to the fact that water is most stable when it has the most hydrogen bonds and that nonpolar molecules decrease the number of those bonds. True or false Read the poem.School looms large, and I feel smallI pause until the door swings wideI hoist my pack, step insideAdjust my cuffs, smooth my hairAnd wonder what Im doing here.Which lines rhyme?lines 1 and 2lines 2 and 3lines 3 and 4lines 4 and 5 PLEASE HELP URGENT!!!!!Need to know cos(G), sin(G), and tan(G) WILL GIVE BRAINLIST Which numbers are rational? Check all that apply. 19 Negative two-fifths 0 StartFraction 4 Over 7 EndFraction 1.091502 2.89 Will mark brainliest!!!solve for each variable gsgyvsjsysgwjyw i hate math sm Turning on your X-Box is an example of___ energy turning into ___ energy.A.electrical,nuclearB.nuclear,soundC.electrical,lightD.electrical,chemical