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How to make super saturated solution?

An aqueous solution can be rendered supersaturated by first dissolving the solute in water at an elevated temperature using enough to give a concentration just under its solubility at that temperature. After the last of the solute crystals have dissolved the solution is cooled.

Answer:

By adding water i guess

Answer: oxide

Explanation:..

Answer:

1. False

Balanced forces would mean all forces acting upon an object would be equal. So there is no movement.

2. True

Unbalanced forces would mean there is a force acting upon a side of tge object, causing it to move in a direction.

Answer:

D

Explanation:

pretty sure D

Time of decays approximately 2.853 days

Given

mass = 320mg iodine-131

No=320 mg

Nt=250 mg

t1/2 = 8 days

Required

t=time of decays

Solution

General formulas used in decay:  

[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]

Input the value

[tex]\tt 250=320.\dfrac{1}{2}^{t/8}\\\\log\dfrac{25}{30}=t/8.log~0.5\rightarrow t=2.853~days[/tex]

Answer:

SeCl₆ < SeF₂ <  SeO₂

Explanation:

To determine the order of the bond angle of the compound, we need to determine the hybridization of each compound given.

For:

SeO₂, The hybridization is sp² because the Se is doubly bonded to O at both sides and Se contains a lone pair of electrons.

SeCl₆, Se is attached to six different Cl atoms via a single bond in a hexagonal shape. Thus, SeCl₆ hybridization is sp³d²

SeF₂, Here, Se is singly bonded to F atoms on both sides and Se contains a lone pair of electrons. The hybridization is sp³

Therefore, the bond angle in sp² = 120°, sp³ = 109.8°, sp³d² = 90°

Hence, the order is:  SeCl₆ < SeF₂ <  SeO₂

Answer:

Percent yield = 87.5%

Explanation:

Given data:

Number of moles of Fe(NO₃)₃ = 2.5 mol

Number of moles of Na₂CO₃ = 3.6 mol

Actual yield of NaNO₃ = 6.3 mol

Percent yield of NaNO₃ = ?

Solution:

Chemical equation:

2Fe(NO₃)₃ + 3Na₂CO₃        →     Fe₂(CO₃)₃ + 6NaNO₃

now we will compare the moles of both reactant with NaNO₃.

                   Fe(NO₃)₃          :              NaNO₃

                       2                   :                  6

                     2.5                  :            6/2×2.5 = 7.5

                  Na₂CO₃             :              NaNO₃

                       3                   :                  6

                     3.6                  :            6/3×3.6 = 7.2

Theoretical yield of NaNO₃ is 7.2 mol.

Percent yield:

Percent yield = actual yield / theoretical yield ×100

Percent yield = 6.3 mol / 7.2mol ×100

Percent yield = 87.5%

Answer:

Valency is the combining power of an element.

There are two types of valency - Electrovalency and Covalency.

Hope it helps!<3

Answer:

Kf being the depression of freezing point constant in the equation:

change in temperature = Kf * molality

Kb being the elevation of boiling point constant in the equation:

change in temperature = Kb * molality

the constant is variable for each solvent.

Explanation:

Answer:

its c

Explanation:

Answer:

b

Explanation:

the answere is b

Answer:

It will make magnesium oxide and water

Explanation:

Answer: the answer is A

Explanation:

Answer:

A. Exposure to air has caused the iron-bearing minerals in the granite to oxidize.

Explanation:

The main cause of granite rust is a metal substance that remains in it's contact over a long period of time. As a result of a moist or wet environment, . a geologist discovers a piece of granite that has a coating of soft, crumbling rust.

Exposure to air has caused the iron-bearing minerals in the granite to oxidize.

Option A. is correct.

Answer:  e. -2 and +1

Explanation:

Oxidation number or oxidation state : It represent the number of electrons lost or gained by the atoms of an element in a compound.

Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation number of the substance increases.

Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation number of the substance gets reduced.

 [tex]Ca(s)+H_2(g)\rightarrow CaH_2[/tex]

The oxidation number of calcium (Ca) in free state is 0 and in [tex]CaH_2[/tex] , it is -2.

The oxidation number of hydrogen in [tex]H_2[/tex] is zero and oxidation number of hydrogen in [tex]CaH_2[/tex]  is +1 as in hydrides hydrogen loses electrons.

The oxidation number of calcium has been +2, and the oxidation number of hydrogen has been -1. Thus, the correct option is A.

The oxidation number can be defined as the number of electrons that have been lost by an atom in a chemical reaction.

The oxidation number can be calculated as the:

The oxidation number of Hydrogen when it combines with the less electronegative element has been -1.

There have been 2 atoms of Hydrogen that lose an electron, thus the total oxidation contribution of hydrogen has been -2.

The oxidation number of hydrogen has been -1.

The oxidation number of Calcium has been:

Ca atom has taken an electron from the hydrogen.

[tex]\rm Ca\;+\;e^-\;\rightarrow\;Ca^-[/tex]

The calcium takes one electron from each atom bonded. Thus the oxidation number of calcium has been +2.

The oxidation number of calcium has been +2, and the oxidation number of hydrogen has been -1. Thus, the correct option is A.

For more information about oxidation numbers, refer to the link:

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Answer:

B.

Explanation:

If it's coming from the south and pushing it north then it'll speed up the marble

Slower growth rate is common characteristic of developing countries. Therefore, the correct option is option A.

A sovereign state that is considered to be developing has a less developed industrial base with an HDI that is lower than other nations. This term is not generally accepted, though. Furthermore, there is no consensus on which nations fall into this category.

Although the phrase "low and middle-income country" (LMIC) is sometimes used synonymously, it only relates to the economies of the nations. In accordance with gross national income per capita, the World Bank divides the world's economy into four categories: high, upper-middle, lower-middle, as well as low income countries. Slower growth rate is common characteristic of developing countries.

Therefore, the correct option is option A.

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Answer:

8.9 mph

Explanation:

Answer:

6Br⁻ + XeO₃ + 6H⁺ → 3Br₂ + Xe + 3H₂O  

Explanation:

First, we need to write the half-reactions:

2Br⁻ → Br₂ + 2e⁻ Oxidation -Balanced yet-

XeO₃ →  Xe Reduction

To balance the reduction in acidic aqueous solution we need to add waters in the other side of the reaction as oxygens are present:

XeO₃ →  Xe + 3H₂O

And H⁺ as hydrogens from water we have:

XeO₃ + 6H⁺ →  Xe + 3H₂O

To balance the charge:

To cancel out the electrons of both half-reaction we need to multiply oxidation 3 times:

6Br⁻ → 3Br₂ + 6e⁻

XeO₃ + 6H⁺ + 6e⁻ →  Xe + 3H₂O  

And the balanced reaction in acidic aqueous solution is the sum of both half-reactions:

Answer:

Covalent bond

Explanation:

I am pretty sure this is the answer

Answer:

Evaporation is very important in the cooling of surfaces. If we put a drop of methylated spirit on our hand the methylated spirit will soon evaporate and our hand feels cold. The molecules of methylated spirit get the energy they need from our hand, leaving the molecules of the hand with less energy and so colder.

The ethylated sprit starts to evaporate from our hand. Evaporation is an endothermic process thus, absorbs the heat energy from our hand make the surface cool.

An endothermic process is the one which absorbs energy from the surroundings to proceed. Thus, an endothermic process make the surroundings cool and make the reaction system hot.

The process which evolves heat energy is called an exothermic process. An exothermic reaction make the surroundings hot sometimes leads to explosion.

Evaporation is the process of conversion of a liquid substance into vapor form. This process needs energy to intake. Hence during evaporation, the heat energy is absorbed from the surroundings make there cool. This is just happening on our hand when sprit evaporates.

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Answer:

When it's gradient decreases

Answer:

A. modern organisms closely resembling fossils

Explanation:

Fossils are defined as the preserved remains or traces of living organisms from past.

Fossils are considered as an evidence for evolution because they represent the existence of life on earth and shows the difference between the life in past that life on earth today. With the help of fossil, it is easy to determine the age of fossils which further help to determine that how modern organisms have evolved from the past.

Hence, the correct answer is "A. modern organisms closely resembling fossils".

Answer:

maybe it does not affect her because uv light is different and has a different reaction to it

Explanation:

can i have brainest please

Answer:

A superposition says that the newest rocks are nearer to the surface and oldest are near the bottom

Answer:

A.

Explanation:

Diatomic elements have to atoms of the element in a molecule.

Diatomic elements are those elements whose atoms combine together to form molecules of the element. The elements that are diatomic in the list are;

Hence, diatomic elements have to atoms of the element in a molecule.

Learn more about diatomic molecules: https://brainly.com/question/4979095

Answer:

Q =  1379.4 J

Explanation:

Given data:

Mass of water = 22  g

Initial temperature = 18°C

Final temperature = 33°C

Heat absorbed = ?

Solution:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

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

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 = 33°C - 18 °C

ΔT =  15°C

Q = 522 g ×4.18 J/g.°C× 15°C

Q =  1379.4 J

The percent by mass sugar of a solution : 11.07%

Given

mass of sugar = 12.45 g

mass of water = 100 g

Required

The percent by mass

Solution

Mass of solution :

[tex]\tt mass~sugar+mass~water=12.45+100=112.45~g[/tex]

Percent mass of sugar :

[tex]\tt \%mass=\dfrac{mass~sugar}{mass~solution}\times 100\%\\\\\%mass=\dfrac{12.45}{112.45}\times 100\%=11.07\%[/tex]

Answer:Long-term drug abuse changes areas in the brain that affect behavior, judgment, learning and memory

Explanation:

Answer:

B. Volcanoes released carbon dioxide into the atmosphere and this allowed for the evolution of oxygen-

breathing life forms

Explanation:

Volcanoes are a major source of carbon dioxide and global warming

Volcanoes absorbed water vapor from the atmosphere and made the planet very dry and difficult to live on, the impact that volcanoes had on the early earth.

A volcano is a crack in a planet's crust, such as the one on Earth, that permits hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Most volcanoes on Earth are located underwater, and they are most frequently found where tectonic plates are diverging or convergent.

The tectonic plates are drifting apart along constructive plate boundaries. To open a fresh passageway for rising hot magma to move on to the surface, the Earth's crust is split apart.

Volcanoes erupt with a tremendously destructive mixture of ash, lava, hot, toxic gases, and rock. Explosions from volcanoes have claimed lives.

Thus, option D is correct.

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