chnge color is a sign of chemical reaction​

Answers

Answer 1
Yeah that’s true because a chemical reaction can’t be changed but a physical change can be changed :)

Related Questions

PLEASE I NEED THIS ANSWER ASAP :(
Impurities that evaporate easily and travel with the water vapor are not removed when using this type of distillation. Explain the reason for this.

Answers

Answer:

Please add as brainlist

Explanation:

Distillation is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components in the mixture. In either case, the process exploits differences in the relative volatility of the mixture's components. In industrial applications, distillation is a unit operation of practically universal importance, but it is a physical separation process, not a chemical reaction.

Can someone pls help

Answers

D, the answer you have.

Have a good one!

how does an electron emit light?

Answers

Answer:

by moving between defined energy levels

true or false, a temperature of 0°F is equal to 32°C

Answers

Answer:

false

Explanation:

Answer:true

Explanation:

can you pls help me with this question

Answers

Answer:

probably c

Explanation:

Answer: I feel like the correct answer is choice C but I really don’t know how to explain it..

A 50 gram sample of radioisotope undergoes 2 half lives. How many grams would remain at the end?

Answers

Answer:

you would need to multiply 50 times 2 wich is 100 so i beleive its 100

Explanation:

using the model, what is the mass of the atom pictured?
A) 3amu
B) 5amu
C) 7amu
D) 9amu

Answers

Answer:

A) 3amu

Explanation:

Identify the charges = Mg2+ F1

Answers

Answer:

its called drop and swap

Explanation:

Elements in a ___ on the Period Table of Elements have similar chemical characteristics and properties.

Answers

The answer is : Group

Which of the following equations of CH4 + Cl2
-
CCl4+ HCl is balanced?
A. O CH4 + Cl2 - CC14+ HCI
B.
CH4 + Cl2 - CCl4 + 4HCI
С.
CH4 + 4Cl2 - CCl4 + 4HCI
D
CH4 + 2Cl2 - CCl4 +2HCI

Answers

Balanced equation : C. CH₄ + 4Cl₂⇒  CCl₄+ 4HCl

Further explanation  

Equalization of chemical reactions can be done using variables. Steps in equalizing the reaction equation:  

1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c, etc.  

2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index (subscript) between reactant and product  

3. Select the coefficient of the substance with the most complex chemical formula equal to 1  

Reaction

CH₄ + Cl₂⇒  CCl₄+ HCl

Give coefficient :

aCH₄ + bCl₂⇒  CCl₄+ cHCl

Make equation :

C, left=a, right=1⇒a=1

H, left=4a, right=c⇒4a=c⇒4.1=c⇒c=4

Cl, left=2b, right=4+c⇒2b=4+c⇒2b=4+4⇒2b=8⇒b=4

The equation becomes :

CH₄ + 4Cl₂⇒  CCl₄+ 4HCl

12) Which model of the atom is thought to be true?
a. Protons, electrons, and neutrons are evenly distributed throughout the volume of
the atom.
b. The nucleus is made of protons, electrons, and neutrons.
c. Electrons are distributed around the nucleus and occupy almost all the volume of
the atom.
d. The nucleus is made of electrons and protons.

Answers

Answer:

B

Explanation:

The neucles is surrounded by electrons. Electrons occupy most of the volume of the atom.

Atomic Model:

Atoms are the smallest unit of elements, which form bonds with others. In an atom, electrons revolve around the nucleus.

The nucleus is composed of positively charged protons and neutrons. The nucleus occupies a very small part of the atom.

Electrons are negatively charged particles, they are found around the nucleus and occupy most of the part of the atom.

Therefore, The neucles is surrounded by electrons. Electrons occupy most of the volume of the atom.

To know more about Atomic Model:

https://brainly.com/question/1596638

Why do nonpolar substances tend to be gases and not liquids or solids?

Answers

Answer:

Because the intermolecular interactions are weaker.

Explanation:

Nonpolar substances do not have dipole-dipole or hydrogen bond interactions, which are strong intermolecular interactions that often make the substance liquid or solid. Instead, they must rely on van der Waals forces, which are relatively weaker interactions that are often insufficient to hold the molecules together in liquid or solid form.

The magnitude of intermolecular association in nonpolar substance is much lower than the magnitude of intermolecular association in polar substances.

Polar substances are those substances in which a permanent dipole exists in the molecule. In a molecule having a permanent dipole, the electronegativity difference between the atoms bonded in the molecule is high.

As a result of this high electronegtivity difference between atoms, the molecules interact more intimately hence polar molecules tend to exist mostly as liquids and gases while nonpolar molecules having less intimate intermolecular interaction via dispersion forces exist mostly as gases.

Learn more: https://brainly.com/question/9352088

Wax melts when it is heated. Which most likely describes what is true of the result of this reaction?

The bonding of the atoms is not the same before and after the change.
The wax has the same density before and after the change.
The same amount of wax exists before and after the change.
The wax cannot be changed back into a solid.
quickly help!!!

Answers

Answer:

The same amount of wax exists before and after the change.

Explanation:

Answer:

c -the same amount of wax exists before and after the change-

Explanation:

I did the quiz (edg.)     :)

Some notes for you:

A physical change is a change in some of the physical properties of matter, but not in its identity.

Wax melting is an energy change, and the energy change can be reversed, which means the wax cools into hard wax again. The wax didn't leave, nor did it somehow get less of it. It stays the same! :)

I hope you have an amazing day, I mean it. God bless you!

john 7:37 <3

may we met again !

i love you,ella

Answers

Answer: When I see you again!

Explanation:

whats the formula for density

Answers

p =[tex]\frac{m}{V}[/tex]

p equals m over V

hope this helps!!

P = density

m = mas

V     =     volume

Explanation:

easy

How many molecules are present in 3HNO4?

1) 14
2) 18
3) 3
4) 4

Answers

Answer:

2

Explanation:

If you take H and N, that is two molecules right off the bat.  If you take O4, that makes 6.  Take the total of all 6, and multiply it by 3, with equals 18.  

3HNO4 = 18

how can you tell if an element has been reduced?

Answers

Answer:

Chemists keep track of how electrons are transferred between atoms in a reaction using an oxidation number. If the oxidation number of an element in the reaction increases or becomes less negative, the element has been oxidized, while a decreased or more negative oxidation number means the element has been reduced.

Answer:

It has more electrons in the product than in the reactant

Explanation:

A p e x

Goodbye Everyone, i will not be on here for awhile because of some things that i really rather not discuss but if you ask why then i guess i'll tell you but if you wanna say goodbye to me then please do so now!
Sincerly,Arri

Answers

Answer:

Which nuclear force holds the nucleus together against the mutual repulsion of the protons in every nucleus larger than Hydrogen’s?

Explanation:

Hi Arri, this is my question, if you cannot answer that it is fine. I hope you are doing well though :) best of luck to you when you are gone. Stay safe, well wishes

A photon has a wavelength of 299 nm. What is the frequency of this photon?
1. 1×10^16 Hz
2. 1×10^15 Hz
3. 6.65 × 10^−37 Hz
4. 6.65 × 10^−28 Hz
5. 0.00100 Hz
6. 1.98 × 10^−31 Hz
7. 8.97 × 10^10 Hz
8. 1×10^6 Hz
9. 6.65 × 10^−18 Hz

Answers

The frequency(f) of this photon : 1 x 10¹⁵ Hz

Further explanation

Radiation energy is absorbed by photons

The energy in one photon can be formulated as

[tex]\large{\boxed{\bold{E\:=\:h\:.\:f}}}[/tex]

Where

h = Planck's constant (6,626.10⁻³⁴ Js)

f = Frequency of electromagnetic waves

f = c / λ

c = speed of light

= 3.10⁸

λ = wavelength

A photon has a wavelength of 299 nm.

λ = 299 nm = 299 x 10⁻⁹ m = 2.99 x 10⁻⁷ m

The frequency  :

[tex]\tt f=\dfrac{3.10^8}{2.99\times 10^{-7}}\\\\f=\boxed{\bold{1\times 10^{15}~Hz}}[/tex]

PLEASE HELP ASAP I NEED THIS THANK YOU SOO MUCH

which of the two chemical equations follow the Law of Conservation of Mass
Equation A: Zn +2HCl —> ZnCl2+ 2H2
Equation B: Zn +2HCl —> ZnCl2 + H2

Answers

Equation A: Zn +2HCl —> ZnCl2+ 2H2

Every organism has a unique common name.
Group of answer choices

True

False
Plz answer the test end in 20 min

Answers

Answer true

Explanation:

Every recognized species on earth (at least in theory) is given a two-part scientific name. ... These naming rules mean that every scientific name is unique. For example, if bluegill sunfish are given the scientific name Lepomis macrochirus, no other animal species can be given the same name

The answer is True, good luck !

______cells have long projections that help carry electrical messages to other cells.
O striated
O nerve
O smooth
O muscle

Answers

Answer: Nerve cells!

its the nerve cell which carry electrical message to others cell.

PHYSICAL SCIENCE PLEASE PLEASE HEP DUE TODAY AT 11!! will give brainly if its correct!! <3333 thank you so muchh!!

Which problem cannot be solved using the scientific method?

determining which student reads faster

discovering who invented the radio

discovering how much salt should be used to boil water faster

determining which laundry detergent works best

Answers

Answer:

I would say discovering who invented the radio.

Explanation:

The other ones can be solved by experiments and the "discovering who invented the radio" cannot be solved by an experiment.

hope this helps.

Answer:

I would say who invented the ratio

Explanation:

Well you dont need to use the scientific method to know WHO discovered it, you use it to determine HOW

It takes much less energy to change the temperature of oil than it does to change the temperature of water

Answers

Answer:

i think so

Explanation:

How many moles are there in 5.2x10^23 atoms of CO2?

Answers

Answer:

0.86 moles of CO₂

Explanation:

Given data:

Number of atoms of CO₂ = 5.2×10²³ atom

Number of moles = ?

Solution:

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

5.2×10²³ atom× 1 mol / 6.022 × 10²³ atoms

0.86 mol

What element is this atom?
(Urgent plz help)

Answers

i’m pretty sure it is Argon

help!!!!! please

there is no question just fill in the question marks

Answers

2 grams :) djdjdjdjsjwjdkndncp

Answer:

32 grams

Explanation:

Ignore the other answer. Two oxygen atoms have a mass of 32 grams. You can also arrive at this answer by subtracting the given values (i.e. 36 - 4 = 32).

1. The heat absorbed when ice melts can
be measured in a unit called a
(1) torr
(2) degree
(3) mole
(4) joule

Answers

4 a joule is the answer

Answer:

joule

Explanation:

The chemical formula for the ionic compound aluminum sulfite is Al2(SO3)3. Explain why there are 2 cations for every 3 anions in this compound.

Answers

Answer:

Explanation:

While trying to write the chemical formula for a compound (a neutral molecule), one must identify and exchange the charge of the cation with that of the anion to become the subscript of one other. For example

Aluminium oxide has Aluminium (Al) and oxygen (O); since Al has a charge of 3+ (the cation) and O has a charge of 2- (the anion), the compound would have it's charges as Al³⁺O²⁻ and when the charges are exchanged to there subscripts, it would form Al₂O₃; thus there would be two cations of aluminium for every three anions of oxygen in order to have a neutral molecule.

This same explanation can be given to Aluminium sulfite. Aluminium sulfite has Aluminium (Al) and sulfite (SO₃). Al has a charge of 3+ (cation) while sulfite has a charge of 2- (anion), with the compound having it's charges as Al³⁺(SO₃)²⁻ and when the charges are exchanged to there subscripts, it would form Al₂(SO₃)₃ and would thus have 2 cations of aluminium (Al³⁺) for every 3 anions of sulfite (SO₃³⁻) in order to have a neutral molecule.

what type of weather forecasting can forecast from 3-7 days? I NEED ANSWERS FAST!!!

Answers

Answer:

WPC medium range forecasting

Explanation:

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