What’s clues indicate that a chemical reaction has occurred?

Whats Clues Indicate That A Chemical Reaction Has Occurred?

Answers

Answer 1

Answer:

Color change, formation of bubbles, and temperature change


Related Questions

in which time period did the first animals that could live both in water and on land appear

Answers

510 million years ago.

how do i find the number if electrons in an element​

Answers

Answer:

by using this formula 2×(n)^२

Answer:

M-A=N

Explanation:

M-A=N

Here is an example.

The equation above means that the atomic number (A) subtracted from the average atomic mass (M) equals the combined amount of neutrons and protons. Since we know that 35 17Cl is Chlorine (this is because Chlorine (Cl) is the 17th number on the periodic table and has the average atomic mass of 35), we can insert our data into the equation and end up with the following:

35-17=18.

From here, we can tell that we have a mix of neutrons and protons, with the total being 18. Since the atomic number is 17, we can reasonably assume that there are 17 protons and 1 neutron.

But we still need to find the number of electrons. Fortunately, the number of electrons is always equivilant to the number of protons and the atomic mass, so we know that the number of electrons is 17.

So, we have;

17 Protons

1 Neutron

17 Electrons

Element of group 2 loses two electrons in the process of a chemical combustion. what is the ionic charge? +2 or -2

Answers

The ionic charge is +2

2. Write down the position of alkaline earth metal in the Modern periodic table What is their valency? ​

Answers

Answer:

they are in group II and they have two electrons in their outermost energy levels ( valency)...is this helpful?

convert 150 K to degrees F

Answers

Answer:

150K is 253.67°F

Explanation:

There is a simple formula to convert from Kelvin to Celsuis;

C° = K - 273.15

    C = 150 - 273.15     C = -123.15

Then you would convert Celsuis into Fahrenheit using the formula:

[tex]F = \frac{9}{5}C + 32\\[/tex]

    [tex]F = \frac{9}{5}(-123.15)+32\\F = 221.67 + 32 \\F = 253.67[/tex]

Is it unbalanced or balanced if hydrogen reacts to iodine?

Answers

Answer:

unbalanced

Explanation:

because it is REACTing.

______________ is a durable material and is widely used for casting, which is a process by which the melted material is poured into a mold. A. Bronze c. Copper b. Silver d. Gold Please select the best answer from the choices provided A B C D.

Answers

The material that has been widely used in casting has been copper. Thus, option C is correct.

Casting has been the process of molding the liquid into a specific shape with the mold. The casting involves the heating of elements and converting them into liquid. The liquid has been poured into the mold and cooling results in the casted material.

The casted material has been selected based on the boiling temperature, cooling temperature, resistivity, cost-effectiveness, and damping ability.

The material that has been consisted of these characteristics has been copper. Thus, copper has been commonly used for casting. Thus, option C is correct.

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50 PIONTS PLZZZ HELP
What volume of 0.100 M K2S solution contains 3.5 g of the solute?

Answers

Answer:

mols solute(K2S) = grams/molar mass = ?

Then M = mols/L. You know M and mols, solve for L.

Explanation:

3.5/0.1

L= 35

Hope this helps!!

Please tell me if I have made a mistake!!

I enjoy learning from them:)

Answer:

0.32L

Explanation:

Use formula of V= wt/mm•M.
To get this information we need to first get the molar mass (mm).
mm:
K - 2 x 39.09
S - 1 x 32.06
K2S - 110.262 g/mol

Now we plug it back into the equation.
3.5g/ (110.262 g/mol) • (0.100M)
= 0.317 L of solution

To round to the correct number of siginficant figures the answer is.
= 0.32 L

an atom has 10 protons and a mass number of 18 how many neutrons does it contain

Answers

Answer:

8 i believe

Explanation:

To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the number of neutrons in the given atom is 8.

What is atom?

Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.

In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron.

Mass number =number of protons + number of neutrons

Atomic number = number of protons= number of electrons

18  =10 + number of neutrons

number of neutrons=8

Therefore, the number of neutrons in the given atom is 8.

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PLEASE…. Select the number line that shows that two opposite numbers have a sum of

0.

3

A.

4321 01 2 3 4 5 6 7 8 9 10 11 12

B.

4 3 2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12

6

С.

-432-10 3 5 6 7 8 9 10 11 12

2

Answers

Answer:

C A

Explanation:

The the number line that shows that two opposite numbers have a sum of 0 is 4 3 2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12. The correct option is B.

What is number line?

A number line is a picture of a graduated straight line that serves as a visual representation of real numbers in elementary mathematics.

Every point on a number line is assumed to be a real number, and every real number is assumed to be a point.

4 3 2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12

We can see from this number line that the inverse of each number is located at an equal distance from 0.

For example, the inverse of 3 is -3, which is the same distance from 0 as 3. Similarly, the inverse of -1 is 1, which is the same distance from 0 as -1.

Thus, the correct option is B.

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If you wanted to make a crucible for melting sodium (Na), which metal would be most suitable for that purpose

Answers

Calcium would be best suitable

To make a crucible for melting sodium (Na), metals that would be most suitable for that purpose are inert metals or metals like alumina.

What are inert metals?

inert metals are those metals that do not react with other highly reactive metals or in the atmosphere due to the absence of one free electron in the outermost orbital.

The sodium metal is kept in the crucible of the inert metal like alumina because sodium has one free electron in the outer shell and catches fire as come into the contact with the air.

Therefore, to make a crucible for melting sodium (Na), metals that would be most suitable for that purpose are inert metals or metals like alumina.

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The density of iron is 7.0 g/cm'. What volume of iron would have a mass of 14.0 g?

Answers

Answer:0.284ib/in 3

Explanation:

[tex]\text{Given that,}\\\\\text{Density of iron, }~ \rho = 7 ~\text{g cm}^{-3} = 7 \times 10^{3}~ \text{kg m}^{-3}\\\\\\\text{Mass, m =14 g =} ~ 14 \times 10^{-3} ~\text{kg}\\\\\\\text{Volume of iron,}~ V = \dfrac{m}{\rho} = \dfrac{14 \times 10^{-3}}{7\times 10^{3}} = 2 \times 10^{-6} ~~ m^3[/tex]

Prepare and name an alcohol by using the following reactants
Hex-1-ene and a water molecule write the complete reaction.

Answers

Answer:

Alcohol will form at more substituted carbon due to carbocation rearrangement so 2-hexanol

Explanation:

Well if it’s acid catalyzed

Hey can anyone pls answer dis in ur own wordssss

Answers

Answer: sorry

Explanation:

j

3.
What relationship do P and V have at a constant temperature? (Direct or Inverse)
1.
What relationship to V and T have at a constant pressure? (Direct or Inverse)
and please don’t put just a link thx

Answers

Answer:

3. Inverse 1. Direct

Explanation:

P- pressure

V - volume

T - temperature

P1*V1 / T1 = P2*V2 / T2 ...... (1)

That's the general gas law with the combined ideas of charles, boyle & lussac.

Whenever you are restricted as "constant" temperature, volume, or pressure...cancel them off of your equation.

in this case 3. is indirectly telling us to cancel the temperature (T).

so we'll be left w P1*V1 = P2*V2

now notice that any relation ship that is multiplied like the one above consists of inversely related quantities. & so we conclude that-

P & V are inversely proportional or have an inverse relationship.

similarly in 1. we'll cancel p off of the general formula (1)

to be left with V1/T1 = V2/T2

also note that quantities involved in division are directly related to each other & hence the answer.

What are the most important topics for revision in chemistry?​

Answers

Answer:

structure of atom

states of matter

classification of elements and periodicity in properties

thermody namic

Equilibrium

Redox reacation

3 examples of how you think cells work in living things.

Answers

Answer:

Cells help the human body in many ways, Red or white blood cells are very important and are commonly spoken when bringing up cells. Plants have cells as well plant cells have special organelles called chloroplasts, which create sugars also known as photosynthesis.

Explanation:

idrk if that helped much-

Select two correct answers.

[]class
[]organism

[] fungi
[]kingdom

Answers

The answer is kingdom and class.
His major groupings in the hierarchy of groups were, the kingdom, phylum, class, order, family, genus, and species; seven levels of groups within groups.

What are the names of the two levels?


Select two correct answers.

Answers

The answer is order and species.

What is the percent of O in
CO2?
(C = 12.01 amu, O = 16.00 amu)
[? ]%

Answers

Answer:

show me a pic?? then I'll lyk

Answer: 33%

Explanation: Because carbon atoms are only 1/3 of the compound since the other 2 atoms are oxygen.

What is the amplitude of the above wave?

Answers

Answer:Amplitude in a longitudinal wave

Explanation:Wave amplitude of a longitudinal wave is the distance between particles of the medium where it is compressed by the wave. Wave amplitude is determined by the energy of the disturbance that causes the wave. A wave caused by a disturbance with more energy has greater amplitude.

Which description of salt is a physical property?

Answers

Answer:

White being the color and coming in small grains.

Explanation:

Physical properties are something you can clearly see about the object.

Answer:

Hey mate......

Explanation:

This is ur answer....

It was in the lesson, the answer is it is solid and does not conduct electricity.

 

Physical Properties                                 Chemical Properties

White cubic crystals                                 Do not undergo combustion

Odorless, salty taste                                 Make ionic bonds easily

As solids, they do not conduct electricity  The product of mixing acids and bases.

Hope it helps!

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Please select the word from the list that best fits the definition
a new energy source found in the ocean that is currently very costly to obtain
nonrenewable resources
renewable resources
methane hydrates
plankton
petroleum
nonliving resources

Answers

Answer:renewable resources

Explanation:

molecules diffusing with the concentration gradient through a protein channel is

Answers

Answer:

Molecules move up the concentration gradient in facilitated diffusion which requires ATP to be used as molecules naturally move from high to low concentration

Explanation:

What mass of sugar and water is needed to make 40 g of 10% solution?​

Answers

10 g of sugar to 40g of water the solution becomes 50 g.

_________________________________________

= 10 / 50 * 100

= 20 %

_____________

Percentage of the sugar solute = Mass of solute / Mass of solution * 100

when an atom in an excited state returns to its ground state it

Answers

Answer:

Inside the Atom

Just like bricks are the building blocks of a home, atoms are the building blocks of matter. Matter is anything that has mass and takes up space (volume). All matter is made up of atoms. The atom has a nucleus, which contains particles of positive charge (protons) and particles of neutral charge (neutrons). Surrounding the nucleus of an atom are shells of electrons - small negatively charged particles. These shells are actually different energy levels and within the energy levels, the electrons orbit the nucleus of the atom.

How many totals atoms are present in the compound : Mg(OH)2

A. 3
B. 4
C. 5
D. 7

Answers

1 atom Mg, 2 atoms O and 2 atoms H.

1 + 2 + 2 = 5, so correct answer is C

Why is the energy supplied by the cooker greater than that calculated in part (a)

Answers

Answer:

136000 J or 136 kJ

Explanation:

Formula

Heat = m * c * deltaH

Givens

m= 0.5 kg

c = 3400 J / (kg * oC)

Deltat = (100oC – 20oC)

deltat = 80oC

Solution

Heat = 0.5 kg * 3400 J/(kg* oC) * 80oC

Heat = 136000 Joules

Heat = 136 kg

Technically there is only 1 place of accuracy.

2. Transfer in energy to reach the highest amount of kinetic energy for both substance B and C.

3. Slowly transfer out energy from each substance. Note the temperature at which each substance changes phase.

​Substance B changed to a liquid at
ANSWER: °C.
Substance C changed to a liquid at
ANSWER: °C.
For Science please answer the questions with the word "ANSWER"

4. Based on your observations above, which substance needed a greater decrease in kinetic energy in order to change phase?
The substance with
(medium or low) ANSWER: Pick which one it is!
attraction needed more energy transferred out in order to change phase.

Answers

The change in phase of a substance is called a physical change. The substance C with low molecular attraction needs more energy transferred out and thus its kinetic energy have to be decreased to change from gas to liquid.

What is energy transfer?

Energy can neither be created nor be destroyed. However it can be transferred from one form to the other and thus total energy of a system is conserved.

In gaseous state molecules or atoms are far apart and have minimum intermolecular forces of attraction whereas in liquid state they have medium molecular attraction and are a bit close than they are in gas state.

When a substance changes from gas state to liquid state its molecules condenses and becomes more close to each other forming higher molecular attraction.

The gas B have medium molecular attraction and thus will easily liquified with minimum energy transfer whereas, gas C is of less molecular attraction having higher kinetic energy and thus more have to transfer more energy out to liquify.

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A teacher wrote the following part of a balanced chemical equation:

2HNO3 + Ca ➡️

To show that chemical reactions conserve matter, how many atoms of hydrogen (H) will there be on the right-hand side of the equation?

A. 3
B. 2
C. 1
D. 6​

Answers

Answer:

answer is 2

Explanation:

just did the quiz

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