which of the following is not true for chemical change

Answers

Answer 1

Answer:

"They can be reversed by physical changes."

Explanation:

A chemical change can form a new substance, can be detected by the change in color and they have properties different from their starting materials.


Related Questions

Describe the difference between at atom and an ion in regards to their substaomic
particles

Answers

Answer:

difference between atom and ion

Explanation:

What is an Atom?

The smallest unit of matter. It is indivisible and consists of neutrons, electrons and protons. Atoms can take part in chemical reactions. Combination of atoms together forms molecule. Always the number of protons and electrons are equal. Independent life may or may not be feasible within a solution. Nucleus of the atom is formed by protons and neutrons. Surrounding the nucleus are the electrons.

What is an Ion?

Atoms where the electrons and protons are not equal are called ions. Ions are charged particles. They can be either positively charged ions or negatively charged ions. If an atom is charged electrically it is considered an ion. If an atom contains maximum number of electrons than protons, then it is called anion. If an atom contains maximum number of protons than electrons, then it is called cation. Independent existence in a solution. When an atom gains or loses electrons, ion is formed.

To make you understand how atom and ion are different from each other, here are the some major differences between atom and ion:

What is the name of the ion with 4 neutrons and 4 electrons with a 1- charge?

A: Hydrogen
B: Berrylium
C: Lithium
D: Helium

Answers

Answer:

C.

Explanation:

I search it on Gøogle

What energy keeps the water cycle going?

Answers

Answer:

the the that keeps the water cycle going is heat

The water cycle that is going is heat

Which of the following has more atoms?
One mole of zinc
One mole of gold
One mole of silver
One mole of magnesium
O They all have the same number of atoms

Answers

Answer:

They all have the same number of atoms

Explanation:

Which of the following has more atoms?

One mole of zinc

One mole of gold

One mole of silver

One mole of magnesium contians  

O They all have the same number of atomst

a mole of anything contains Avogadros number of 6.022X10^23  things

which has the greatest number of thing? a dozen eggs, a dozen cookies, a dozen pizzas?

a dozen is a number means 12

a mole is a number that that means 6.022 X 10^23 you calculate the molar mass from the chemical formula, but every j mole contains 6.022X10^23

particles.

just like every dozen contains 12

so

They all have the same number of atoms

Which pair of compounds has the same empirical formula? C_{3}*H_{8} and C_{3}*H. C_{2}*H_{2} and C_{2}*H C_{4}*H_{10} and C_{6}*H C_{4}*H_{10} and C_{2}*H_{5}

Answers

Considering the definition of empirical and molecular formula, the pair of compounds C₄H₁₀ and C₂H₅ has the same empirical formula.

The empirical formula is the simplest expression to represent a chemical compound and indicates the elements that are present and the minimum proportion in whole numbers that there are between their atoms. This formula is also known as the "minimum formula".

On the other side, the molecular formula is the chemical formula that indicates the number and type of different atoms present in the molecule. But unlike the chemical formula, it shows the actual number of atoms that make up a molecule.

In this case, you can observe that if you divide the amount of each element by 2 in compound C₄H₁₀, you get C₂H₅, which is the empirical formula of the compound.

Finally, the pair of compounds C₄H₁₀ and C₂H₅ has the same empirical formula.

Learn more:

https://brainly.com/question/6960643

Protons and neutrons have opposite, but equal magnitude, charges. An atom contains the same number of protons and electrons Neutrons and electrons are found in the nucleus of an atom. Protons have about the same mass as electrons. Electrons make up most of the mass of an atom. which one is true about subatomic particles

Answers

Answer:

the true statement is an atom contains the same number of electron and proton

Explanation:

let us see the behaviour of the sub atomic particles

nutrons and protons found in the nucleus of an atoman atom have the same number of electron and proton but they have different chargenutron is chargeless particlemost mass of the atom concentrated in the nucleus of an atomelectrons have almost 0 mass from an atommass of proton and mass of nutron are equvalent or almost equal

there are many properties of subatomic particles i have listed some of them above .

I think it is help ful for you

Give one example of a question that science could test. Then, explain in your own words why it is an example of a scientific question. Please!

Answers

Answer:

Questions are an essential part of science. ... They state the final question in a way that can be answered by investigation or experiment. A good scientific question is: “What effect does the pH of water have on radish seed germination?” Good scientific questions are defined, measurable, and controllable.

What is metabolism? I know the answer.

Answers

Answer:

Metabolism is the set of life-sustaining chemical reactions in organisms. The three main purposes of metabolism are: the conversion of the energy in food to energy available to run cellular processes

Explanation:

What is the angle between adjacent sp hybrid orbitals?

Answers

Answer:

180 degrees

Explanation:

sp hybridization generates orbitals that overlap linearly, generating a straight line. This leads to an angle measurement of 180 degrees.

180 degrees is your answer

adjoa's gross salary for last month was ghs 4687.24. if ghs 421.78 was deducted from adjoa's salary pay,how much take home pay did adjoa earned this past month?​

Answers

Since Ghs. 421.78 was deducted from Adjoa's salary pay, her take home pay is Ghs. 4265.46.

Given the following data:

Adjoa's gross salary = Ghs. 4687.24.Deduction = Ghs. 421.78

Gross profit can be defined as the profit earned by a business after subtracting its cost of manufacturing and distributing goods from its total revenue (sales).

On a related note, gross salary is the amount of money earned by an individual before any deduction such as tax.

To find how much take home pay Adjoa earned this past month:

[tex]Take\;home = Gross\;salary - deduction\\\\Take\;home = 4687.24 - 421.78[/tex]

Take home = Ghs. 4265.46.

Read more: https://brainly.com/question/25273589

Which describes a chemical change? (Select all that apply.)

A new substance is created.
A phase change is occurring.
It is a permanent change.
It can be a physical change.

Answers

Explanation:

it is a permanent change

Answer: It is a permenat change

Explanation: Because you are creating it into something else and when it turns into that thing it stays like that permanatly.

Identify which of the following equations are balanced and which ones are not balanced

A. CH4 +202 —> CO2 + 2H20

B. 6CO2 + 6H2O—> C6H12O6+602

C. 2Na + H2O —> 2NaOH+ H2

Answers

Answer:

A. balancedB. UnblalancedC. Unbalanced

Explanation:

The green light emitted by a stoplight has a wavelength of 505 nm. What is the frequency of this photon? (c = 3.00 × 10⁸ m/s).

Answers

Answer:

5.9405*10^14 Hz

Explanation:

Remember the equation c=v*λ

v=frequency

λ=wavelength

By manipulating the equation, we can get it in terms of frequency:

c/λ=v

Now convert wavelength to meters (1nm=m*10^-9)

5.05*10^-7m (2 decimal places were shifted to make the number between 1-10, hence the -7 exponent)

Use the manipulated equation:

(3.00*10^8)/(5.05*10^-7), which yields:

5.9405*10^14 Hz (or s^-1)

The frequency of the photon will be "[tex]5.9405\times 10^{14} \ Hz[/tex]".

According to the question,

Wavelength,

[tex]\lambda = 505 \ nm[/tex]

or,

          [tex]= 5.05\times 10^{-7} \ m[/tex]

As we know the equation,

→ [tex]c = v\times \lambda[/tex]

or,

→ [tex]v = \frac{c}{\lambda}[/tex]

By putting the values, we get

     [tex]= \frac{3.00\times 10^8}{5.05\times 10^{-7}}[/tex]

     [tex]= 5.9405\times 10^{14} \ Hz[/tex]

Thus the above answer is right.

Learn more:

https://brainly.com/question/14523087

Write a balanced chemical equation based on the following description:
the reaction of gaseous tricarbon octahydride with oxygen gas produces gaseous carbon dioxide and water vapor

Answers

Answer:

C3H8(g) + 5O2(g) = 3CO2(g) + 4H2O(g)

Explanation:

What mass of carbon dioxide is produced from the complete combustion of 4.60x10^-3g of methane?

Answers

Answer:

Explanation:

CH4 + 2O2 ==> CO2 + 2H2O

mols CH4 = grams/molar mass

Using the coefficients in the balanced equation, convert mols CH4 to mols CO2.

Now convert mols CO2 to grams. g = mols x molar mass.

1. ¿Cuál de los factores se deben emplear para convertir: a. ¿Número de moles de cloro en número de moles de NaCl? b. Moles de sodio a moles de cloro C. Moles de cloro a moles de sodio. 2 Na + CI, - 2 Naci
Ayudaaa​

Answers

Answer:

Número de moles de cloro en número de moles de NaCl

Explanation:

espero que si sea la correcta

1. Oxygen was discovered by Joseph Priestley in 1774 when he heated mercury (II) oxide, HgO, to decompose it to form its constituent elements. How many moles of mercury (II) oxide are needed to produce 125 g of oxygen?

Given:
Unknown:
Mole ratio:
Solution:


2. In a blast furnace, iron (III) oxide is used to produce iron by the following (unbalanced) reaction:
Fe2O3(s) + CO(g)  Fe(s) + CO2(g)
If 4000 g of Fe2O3 is available to react, how many moles of CO are needed?
Given:
Unknown:
Mole ratio:
Solution:

Final answer:


ugh pls help:(

Answers

Answer:

1. 7.81 moles HgO

2. n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.

Explanation:

How many moles of mercury (II) oxide are needed to produce 125 g of oxygen?

2HgO ==> 2Hg + O2  

125 g O2 x 1 mol O2/32 g x 2 mol HgO / mol O2 = 7.81 moles HgO

------------------------------------------------------------------------------------------------------------

If 4000 g of Fe2O3 is available to react, how many moles of CO are needed?

The no. of moles of CO are needed = 75.15 mol.

Fe₂O₃ + 3CO → 2Fe + 3CO₂,

It is clear that 1 mol of Fe₂O₃ reacts with 3 mol of CO to produce 2 mol of Fe and 3 mol of CO₂.

If 4.00 kg Fe₂O₃ are available to react, how many moles of CO are needed?

We need to calculate the no. of moles of 4.00 kg Fe₂O₃:

n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.

Using cross multiplication:

1 mol of Fe₂O₃ need  → 3 mol of CO to react completely, from stichiometry.

25.05 mol of Fe₂O₃ need  → ??? mol of CO to react completely.

The no. of moles of CO are needed = (3 mol)(25.05 mol)/(1 mol) = 75.15 mol.

According to stoichiometry of the chemical equation, if 4000 g of iron oxide  is available to react,25.04 moles of CO are needed.

What is chemical equation?

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .

The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.

159.69 g iron oxide gives 28 g CO thus 4000 g iron oxide will give 4000×28/159.69=701.35 g which is 701.35/28=25.04 moles.

Learn more about chemical equation,here:

https://brainly.com/question/28294176

#SPJ2


The electronic transition in a hydrogen atom from n = 6 to n = 3 emits electromagnetic radiation having a higher frequency than a transition
from n = 5 to n = 3

Answers

Hoy !have a great day

Why would you expect the materials used to make pot holders to be poor conductors of heat?

Answers

Answer:

Pot holders are meant to protect your hand from the heat of the pot, and so it would need to be a poor conductor of heat in order to do its job correctly. Silicon dioxide is a solid at room temperature and methanol is a liquid.

How many grams are in 0.990 mol of neon?
mass in grams:

Answers

Explanation:

Multiply the given moles times the molar mass of neon, 20.180 g/mol (periodic table).

Answer:

Multiply the supplied moles by 20.180 g/mol, the molar mass of neon (periodic table).

Explanation:

If the atomic mass of an atom is 16 and its atomic number is 7. how many
neutrons does it have?

Answers

Answer:

8

Explanation:

Substance whose smell changes in acidic or basic solutions

Answers

Answer:

Olfactory indicators

Explanation:

The substance whose odour changes in an acidic of basic medium are called olfactory indicators. In an olfactory indicator , smell varies depending on whether it is mixed with an acidic or basic solution.

Why do you think dark surfaces absorb radiation better than light surfaces?

Answers

Your answer→ The lighter side absorbs less of the incident light, reflecting some of the energy. Darker materials also emit radiation more readily than light-colored materials, so they cool faster.

To solve this we must be knowing each and every concept related to radiation. Therefore, dark surfaces absorb radiation better than light surfaces as dark surfaces absorbs light of all wavelengths.

What is radiation?

According to the energy of the emitted particles, radiation is frequently classified as being either ionizing or non-ionizing. More than 10 eV is often carried by ionizing radiation, which is sufficient to ionize atoms as well as molecules and rupture chemical bonds.

The word refers to radiation having an energy level high enough to ionize atoms, or to remove electrons from atoms to produce ions. Whenever an electron is removed from an atom's electron shell, or, as we may say, when it is "tried to knock out," the action of ionization takes place. Dark surfaces absorb radiation better than light surfaces as dark surfaces absorbs light of all wavelengths.

Therefore, dark surfaces absorb radiation better than light surfaces as dark surfaces absorbs light of all wavelengths.

To know more about radiation

https://brainly.com/question/13163856

#SPJ2

Nguyên tử khối của đồng

Answers

Answer:

huwattt

Explanation:

i can't understand

Vitamin D is produced in the skin when 7-dehydrocholesterol reacts with UVB rays (ultraviolet B) having wavelengths between
270 nm and 300 nm. What is the energy range Emin < E< Emax of the UVB photons?

Answers

The energy range expected is 6.6 × 10^-19 J < E < 7.33 × 10^-19 J

The energy of the photon is given by;

E = hc/λ

E = energy of the photon

h = Plank's constant

c = speed of light

λ = wavelength of light

For the upper boundary range;

E = ?

h = 6.6 × 10^-34 Js

c = 3  × 10^8 m/s

λ = 270 × 10^-9

E =  6.6 × 10^-34 Js × 3  × 10^8 m/s / 270 × 10^-9

E = 7.33 × 10^-19 J

For the lower range;

E = ?

h = 6.6 × 10^-34 Js

c = 3  × 10^8 m/s

λ =300 × 10^-9

E =  6.6 × 10^-34 Js × 3  × 10^8 m/s / 300 × 10^-9

E = 6.6 × 10^-19 J

Hence, the energy range 6.6 × 10^-19 J < E <  7.33 × 10^-19 J

Learn more: https://brainly.com/question/24857760

HELP PLEASEEEEEEEEEEEEEEEEEEE

Answers

Answer:

1-air

2-decrease

3-water

4-gas

5-liquid

I THINK the answer to part b is A but I am not entirely sure

Explanation:

Select reason(s) why 1-hydroxy-2-methyl-5-isopropylbenzene is an incorrect systematic name for carvacrol.

a. If named with benzene as the parent, the methyl group needs to have the first locant in order to minimize the number of the third locant.
b. The substituents are not listed alphabetically.
c. If named with benzene as the parent, the hydroxyl group needs to have the first locant in order to minimize the number of the third locant.
d. The substituents are not listed in order of increasing mass.

Answers

The reason why 1-hydroxy-2-methyl-5-isopropylbenzene is not the correct systematic name for carvacrol is because the substituents are not listed alphabetically.

IUPAC nomenclature provides the correct and acceptable system of naming organic compounds which are internationally acceptable among scientists.

According to the rules of IUPAC nomenclature, compounds are named in alphabetical order. The names of the locants are ordered in such a way that they have the lowest number. Following IUPAC nomenclature, the correct name of the compound ought to be, 1-hydroxy-5-isopropyl-2-methylbenzene.

Learn more: https://brainly.com/question/11587934

Ribosome factory part or worker

Answers

Ribosome would be considered a factory “worker” as they *produce* proteins!

state why vulcanologist make predications about when a volcano will erupt

Answers

Answer:

They want to know how long it has been since it last erupted.

Explanation:

Scientists study a volcano's history to try to predict when it will next erupt.  They also want to know the time span between its previous eruptions

detailed description of how group 1 atoms bond with group 7 atoms​

Answers

Answer:

group 7 atoms react

Explanation:

When a group 7 element takes part in a reaction, its atoms each gain one electron. These atoms form negatively charged ions . The ions have a stable arrangement of electrons, with a complete outer shell.

Other Questions
Choose the solution for the equation 3(p+8) = 2(2p-1)a) p=24b) p=26c) p=-26d) p=-24 Solve for the variable g+3.42=7.98g = ? A minister is an example of someone with an achieved status.Please select the best answer from the choices providedOF When a biological vector is used, which process is used to ensure there are large amounts of DNA?cloningelectrophoresisgenetic engineeringgene isolation Please Please Help Me. Put the following equation of a line into slope-intercept form, simplifying all fractions.2y-2x= -14 Which step in the writing process is the studentmissing?Read this student's description of his research plan.I began by deciding on a research topic based on theprompt. I continued by creating a schedule to plan thetime each step would take. Then I began researchingand taking notes. I organized the information I foundand then wrote my draft. Finally, I revised my draft forreadability and published my essayDetermine the age of the audience,Develop effective research questions,Include break times to regroup ideas,Create the hook based on research. You can substitute a number for a variable and then find the value of the expression. This is called _________________ the expression. To select the proper twist drill, one should checkdrill speedObsize, sharpness and type of shanklength of the drill cutting lipsOdlubrication needed Which element is most likely to lose electrons in a chemical reaction?Group of answer choicesMgClSBr How did Eleanor Roosevelt become interested in their work? French Test1. Ces deux enfants..trs intelligents. sontessuissommestesestOther:2. Marie..petite mais elle comprendra. sontsommesestessuistesOther:3. Je..tudiante en facult de lettres. *estessuissommessonttesOther:4. Tu.. trs jeune et tu peux attendre l'anne prochaine pour te prsenter. estsuisessonttessommesOther:5. Vous..l ! Tant mieux, je vais pouvoir partir. *sommestessuisestessontOther:6. Cette solution, .. - elle valable dans toutes les situations? estessontsommessuistesOther:This is a required question7. Merci ! Elles..arrives chez nous maintenant. sommestesessontsuisestOther:8. Il..trs mchant ! Mais ne l'coute pas. estsonttessommessuisesOther:9. Nous..nombreux venir nous entraner ici. sommessuisessontesttesOther:10. La population..avertie depuis ce matin. *estesestsommessontsuisOther:11. Elle n'.....pas de dents, tu ne risques rien. *avezaiavonsasontaOther:12. Nous..chang de moyen de communication. *aavezontaiasavonsOther:13. Tu.. le choix, fais comme tu veux. *ontaiavonsaasavezOther:14. Ah ! j'..... l'honneur de le connatre depuis de longues annes. *asaiontaavonsavezOther:15... -vous un crdit en cours ? *avezasavonsaaiontOther:16... -je vous donne un rendez-vous aujourd'hui ? Je ne me souviens plus. aiavonsasontavezaOther:17. Nous.. pay toutes les charges. *1 pointaiasavezaavonsontOther:18. J'.....80 ans, mais je me sens toujours jeune. *1 pointasaavonsavezaiontOther:suis19. Ils..une belle voiture mais ne s'en servent pas. *avezasavonsaiontaOther:20. Mes parents..une carte bancaire. aaiavezasavonsont what is 3/4 times 8/9?! plzzzzzzzzzzzzzzzzzzzzzzzzzzzzz you divide a number by 3, add 6, then subtract 7. The result is 4. What is the number? plssssssssssssssssssssssssssssssssssssssssssssss A construction company can remove 6 3/4 metric tons of dirt from a construction site in 1 7/8 hours. What is the unit rate in metric tons per hour? Write your answer as a fraction or a mixed number in simplest form. Describe the main structures involved in photosynthesis. Graph the inequality 4x-12y You are at a rest stop 250 miles north of New York City. You then travel north at a constant velocity of 65 miles per hour for 2.0 hours. Describe your location relative to New York City. Find the value of x. Harold bought 3 pounds of red apples and 4.2 pounds of green apples from a grocery store, where both kinds of apples are $1.75 a pound. How much did Harold spend on apples?