Which of the following are evidence that a chemical reaction has occurred?

A. Two liquids are combined and a gas is released
B. A substance is added to water and dissolves
C. Two liquids are combined and a solid precipitate forms
D. A new substance is formed
E. A single reactant changes from a liquid to a solid

Answer:

nooo all cells are not same

Explanation:

like heart cell, muscles cell

100% no.

Blood cells and white cells, for example, have different colors.

White cells are larger with not much of them while blood cells are opposite.

They are in our body

Answer:

velocity

Explanation:

"Speed is a measure of the distance an object travels per unit of time."

Answer:

21 mol of O₂ will react

Explanation:

Based on the combustion of ethanol:

C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(g)

1 mole of ethanol, C₂H₅OH reacts with 3 moles of O₂

With this ratio of 1 mol C₂H₅OH / 3 moles O₂ we can solve the moles of O₂ that react with 7mol of ethanol:

7 mol C₂H₅OH * (3mol O₂ / 1 mol C₂H₅OH) =

Answer:

vapor pressure.

Explanation:

Answer:

I think it is vapor pressure or air pressure

Answer:

begin to move

Explanation:

When electric charges begin to move, this is when magnetism takes place.

Hope this helped!

Answer:

26. Single Displacement

27. Synthesis

28. Decomposition

29. Combustion

30. Double Displacement

31. Combustion

32. Double Displacement

33. Decomposition

Explanation:

Hope it helped!

Answer:

0.96 mol AG

Explanation:

To see the number of atoms of an element, we need to multiply stoichiometry of that molecule to the number that is written on the foot of element. Thus the balanced reaction is

[tex]\rm Mg+2AgNO_{3}\rightarrow Mg(NO_{3})_{2}+2Ag[/tex]

And the mole of silver produced from  0.480 mol is  0.96 mol    

Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side.

The unbalanced equation is

[tex]\rm Mg+AgNO_{3}\rightarrow Mg(NO_{3})_{2}+Ag[/tex]

Magnesium atoms on reactant and product side is 1.

Nitrogen atoms on reactant side is 1 and on product side it is 2 so, multiply [tex]AgNO_{3}[/tex] by 2, now the reaction becomes

[tex]\rm Mg+2AgNO_{3}\rightarrow Mg(NO_{3})_{2}+Ag[/tex]

Silver atom on reactant side is 2 while on product side it is 1 so, multiply Ag by 2, now the balanced equation is

[tex]\rm Mg+2AgNO_{3}\rightarrow Mg(NO_{3})_{2}+2Ag[/tex]

The mole ratio of Mg to silver is 1:2

1mole of Mg produce=2 mole of Silver

0.480 mol of magnesium produce= 2×0.480=0.96 mol fo silver

Thus the balanced reaction is

[tex]\rm Mg+2AgNO_{3}\rightarrow Mg(NO_{3})_{2}+2Ag[/tex]

And the mole of silver produced from  0.480 mol is  0.96 mol        

Learn more about the balanced equation, here:

https://brainly.com/question/7181548

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Answer:

a.)Semiconductors are more conductive than a nonmetal and less conductive than a metal.

Explanation:

Answer: A is your answer

Explanation: yor welcome =]=]=]=]

Answer:

____________________________________________________________________________

Answer:

Radiology departments in hospitals use x-rays, MRIs, CT scans, etc. on a daily basis, meaning they are heavily exposed to radiation without protective equipment, and said exposure can cause cancer down the line and shorten their life significantly. To prevent this from happening, they give the radiologist (and the patient) with equipment with lead (and other materials) which reflects or absorbs the radiation from these scans, including shoes with special soles. These shoes are most likely worn due to the radiation left in the scanning room floors after scans. Radiologists also go to a special room with heavy radiation protection where they can activate and monitor the scan.

Answer:

it depends on mass and speed

Answer:

See explanation

Explanation:

We separate substances based on their important properties such as reaction to heat, solubility in water, magnetic properties, etc.

To separate sodium chloride and potassium trioxonitrateV, we need to heat the solution. KNO3 dissolves at a high temperature and crystallizes out as the solution is cooled.

Hence when we heat the solution, KNO3 dissolves, as we cool the solution, solid KNO3 crystals are obtained while NaCl remains in solution.  We have now separated the two salts in the solution.

Note that the solubility of NaCl is almost independent of temperature.

Answer:

D. The one that runs out first in the reaction

Explanation:

Limiting reagent is the one that limit the yield of product because of its lower amount and run out first. Lets take an example,

Mass of calcium carbonate = 25 g

Mass of hydrochloric acid = 13.0 g

Mass of calcium chloride produced = ?

Chemical equation:

CaCO₃ + 2HCl  → CaCl₂  + H₂O + CO₂

Number of moles of CaCO₃:

Number of moles of CaCO₃ = Mass /molar mass

Number of moles of CaCO₃= 25.0 g / 100.1 g/mol

Number of moles of CaCO₃ = 0.25 mol

Number of moles of HCl:

Number of moles of HCl = Mass /molar mass

Number of moles of HCl = 13.0 g / 36.5 g/mol

Number of moles of HCl = 0.36 mol

Now we will compare the moles of CaCl₂ with HCl and CaCO₃ .

                  CaCO₃      :               CaCl₂

                  1               :               1

                 0.25           :            0.25

                HCl              :                CaCl₂

                 2                :                 1

                 0.36            :               1/2 × 0.36 = 0.18 mol

The number of moles of CaCl₂ produced by HCl are less it will be limiting reactant.

Answer:

D. The one that runs out first in the reaction​

Explanation:

it was right

Answer:

B.Mendeleev

Explanation:

I think this is right

Answer:

In first shell 2 electrons are present and 7 electrons are present in last shell

Explanation:

Explanation:

Why brunojg driftwood makes colored fire... Burning driftwood, especially from the ocean gets a fire with blue and lavender flames. The colored fire comes from excitation of the metal salts that have soaked I to the wood. While the flames arepretty, the smoke give off of the fire is toxic

The mass of Nickel(II) phosphate = 5508.646 g

Given

9.06 x 10²⁴ of Nickel(II) phosphate

Required

The mass

Solution

1 mol = 6.02 x 10²³ particles(molecules,ions, atoms)⇒Avogadro's number

So mol Nickel(II) phosphate :

n = N : No

n = 9.06 x 10²⁴ : 6.02 x 10²³

n = 15.05

mass of Nickel(II) phosphate(Ni₃(PO₄)₂ , MW=366.023 g/mol) :

mass = mol x MW

mass = 15.05 x 366.023

mass = 5508.646 g

Answer:

35 minutes

Explanation:

The flow rate of the stream is the rate of volume of water with respect to time. It expresses the volume of water flowing per unit time.

Flow rate = [tex]\frac{volume}{time}[/tex]

From the given question,

average flow rate of the stream = 420 cubic meters per minute, and the required volume = 14700 cubic meters.

So that;

time = [tex]\frac{volume}{flow rate}[/tex]

       = [tex]\frac{14700}{420}[/tex]

       = 35

time = 35 minutes

Therefore, with the given average flow rate, the steam will produce 14,700 cubic meters of water in 35 minutes.

Answer: Option (C) is the correct answer.

Explanation:

When electrons between two combining adjacent atoms attain positions which leads to the formation of temporary charges over the atoms then there exists a temporary adjacent force called London dispersion force.

This force is also known as induced dipole-induced dipole attraction.

When the temperature is lowered to a certain point then London forces causes the non-polar substances to condense to liquid and then they freeze into solids.

Answer:

1280J are required.

Explanation:

Heat of fusion is defined as the amount of heat required to change its state from liquid to solid at its melting point at constant pressure.

As heat of fusion of gold is 64J/g, there are required 64J to melt 1g of gold at its melting point. The energy required to melt 20g is:

20g * (64J/g) =

1280J are required

Answer and Explanation:

Sodium has 11 protons.

To know how many protons are in an element on the periodic table, all you have to do is look at the atomic number. The atomic number is the same as the amount of protons.

The amount of protons defines the element, which is why it appears on the element description as the atomic number.

Hope this helps!

#teamtrees #WAP (Water And Plant)

Answer:

StartFraction 37 over 2 EndFraction divided by StartFraction 17 over 4 EndFraction

Explanation:

This problem deals with solving and find the rate at which water flowed out of the tank.

Quantity of water that flowed out of the tank = 18[tex]\frac{1}{2}[/tex] gallons   = [tex]\frac{37}{2}[/tex]gallons

Time taken  = 4[tex]\frac{1}{4}[/tex]hr  = [tex]\frac{17}{4}[/tex]hr

Now to find the rate;

  Rate of water flow = [tex]\frac{Quantity of water }{Time taken}[/tex]  

 Rate of water flow  = [tex]\frac{37}{2}[/tex] / [tex]\frac{17}{4}[/tex]  

                                 =  [tex]\frac{37}{2}[/tex] x [tex]\frac{4}{17}[/tex]

                                 = [tex]\frac{74}{17}[/tex]gallons/hr

Answer:

D

37/2 divided by 17/4

Explanation:

edge 2020

Answer:

Describes its potential to undergo some chemical change or reaction by virtue of its composition

Answer:

20%

Explanation:

I HOPE THIS HELPS YOUUUU

Answer:

20%

Explanation:

0.6 g NaCl

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[RxN - Balanced] Na₂CO₃ (aq) + CaCl₂ (aq) → CaCO₃ (s) + 2NaCl (aq)

[Given] 0.5 g Na₂CO₃ reacted with excess CaCl₂

Step 2: Identify Conversions

[RxN] Na₂CO₃ → 2NaCl

Molar Mass of Na - 22.99 g/mol

Molar Mass of C - 12.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of Cl - 35.45 g/mol

Molar Mass of Na₂CO₃ - 2(22.99) + 12.01 + 3(16.00) = 105.99 g/mol

Molar Mass of NaCl - 22.99 + 35.45 = 58.44 g/mol

Step 3: Stoichiometry

Step 4: Check

Follow sig fig rules and round. We are given 1 sig fig.

0.551373 g NaCl ≈ 0.6 g NaCl

Answer:

The frequency of the wave is 2Hz.

Explanation:

The frequency of a wave is the number of waves that pass a fixed point in a given amount of time. It can be measured by counting the number of crests that pass the point in a given time period. The higher the number is, the greater is the frequency of the wave.

So, by counting the number of times the coils in the spring are widely spaced, which is 2 times in 1 second, we get the frequency of the wave.

Answer:

The answer is 2.

Explanation:

Hope this helps ;)

Answer:

h

Explanation:

get into