Answer them please thanks

Answer:

The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.

Explanation:

The hydrochloric acid and sodium carbonate reaction was exothermic that caused the pressure to decrease. The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.

In exothermic reactions, energy is produced in the form of heat or light.

Answer: Spun yarn is made by twisting staple fibers together

To make a cohesive thread Or “single”. Twisting fibers, into yarn in the process called spinning can be dated back to the upper Paleolithic. Yarn spinning was one of the first processes to be industrialized.

Explanation:

Answer: frfg6

Explanation: 655tyyt

Answer:

720

Explanation: study island

Answer:

720

Explanation:

This follows a simple conversion technique. Basically what the question is trying to say here is to convert 29.1 inHg to mmHg. 1 inHg is equal to 25.4 mmHg so 29.1 inHg would be equal to [tex]25.4 * 29.1[/tex] which when evaluated turns out to be: [tex]739.14[/tex]. :D

The pressure will be 739.14 mm Hg.

The SI unit measuring pressure would be the pascal, which measures the force of each unit area of the surface.

Calculation of pressure

It is known that 1inHg = 25.4 mm Hg.

Hence, the pressure = 25.4 × 29.1 = 739.14 mm Hg

Therefore, the pressure will be 739.14 mm Hg.

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Answer: It's D

Explanation:

Answer:

The correct answer is "[tex]\frac{0.65}{V} \ percent[/tex]".

Explanation:

The given values are:

[tex]M_r=0.130 \ g[/tex]

[tex]M_o=20 \ g/L\times V(L)[/tex]

     [tex]=20 \ V[/tex]

As we know,

⇒ [tex]Recovery \ percent=\frac{Amount \ of \ substance \ recovered}{Amount \ of \ substance \ originally \ taken}\times 100[/tex]

On substituting the given values, we get

                                [tex]=\frac{0.130}{20 \ V}\times 100[/tex]

                                [tex]=\frac{0.65}{V} \ percent[/tex]

Note: percent = %

Answer:

m*s⁻¹.

Explanation:

Hello!

In this case, since the frequency measures how repetitive an event is per unit of time, for instance the laps a car drives every 5 minutes or something similar, we can infer it has units of event/time; in such a way, the unit m*s⁻¹ is not a proper unit of frequency because it is a proper unit of velocity which is the distance traveled per unit of time.

In such a way, Hz (hertz), s⁻¹ and 1/s are possible ways frequency can be represented.

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Answer:

1. a

Explanation:

2. c

Answer:

1 is A number two is C

Answer:

Atomic size is the distance from the nucleus to the valence shell where the valence electrons are located. The separation that occurs because electrons have the same charge. The number of protons in the nucleus. The core electrons in an atom interfere with the attraction of the nucleus for the outermost electrons.

Explanation:

That would be B I believe, but please correct me if I'm wrong.

Answer:

We can see that the atomic radius decreases across every row.

Explanation:

I will comment more below.

The elements that represent the highest points on the graph are all elements of group 1 and occur at the head of the period to which they belong.

The periodic table is an arrangement of elements in groups and periods. The elements in the same group have the same number of valence electrons while the elements in the same period have the same number of shells.

Looking at the graph, we can see that the high points in the graph all correspond to the group 1 elements; sodium, potassium, rubidium and cesium.The have the highest atomic radii in the period. Atomic radii increases down the group but decreases across the period. Remember that these elements are at the head of the period to which they belong hence they have the highest atomic radii.

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Answer:

it's answer is

element of an atom ✌️

Answer:

D. Supported by observations

Explanation:

Because theories change over time, they both need to be proven, they do not go off of consensus, but they do need to be supported by observations.

HOPE IT HELPS❣️

Answer:

It's B

Explanation:

I got it right on edjenuity

The most likely outcome of the retrofitting of a nuclear power plant is that it will be able to reprocess its used uranium fuel. Therefore, option C is correct.

A nuclear power plant is a facility that generates electricity by harnessing the heat produced by nuclear reactions. At the heart of a nuclear power plant is the reactor, where a controlled chain reaction of nuclear fission occurs.

Reprocessing is a process by which the used nuclear fuel is chemically treated to separate out and recover the unused uranium and plutonium, which can then be reused as fuel. This reduces the amount of radioactive waste produced by the plant and also extends the life of the uranium fuel.

The fission reactions to fusion reactions is not currently a viable option for power generation, and the idea that a retrofitting would eliminate radioactive wastes is unlikely, as nuclear power plants will always produce some amount of radioactive waste.

Thus, option C is correct.

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Answer:

349.22°C

Explanation:

Let the final temperature of the two pieces of metal be x.

Now, the warmer metal which is C u reduces from 475°C to x. Thus Δt for C u is; Δt1 = 475 - x.

The cooler metal Cr increases in temperature from 265°C to x. Thus, it's change in temperature is Δt for Cr is; Δt2 = x - 265.

Now from conservation of energy, the amount of energy leaving the C u metal is equal to the amount of energy entering the Cr metal.

Thus;

q_lost = q_gain

Where;

q_lost = m1•c1•Δt1

q_gained = m2•c2•Δt2

Now, c1 & c2 are the specific heat capacity of C u and Cr respectively.

From online tables, c1 = 0.385 J/g°C and c2 = 0.46 J/g°C

We are given;

m1 = 12g and m2 = 15g

Thus;

12 × 0.385 × (475 - x) = 15 × 0.46 × (x - 265)

2194.5 - 4.62x = 6.9x - 1828.5

6.9x + 4.62x = 2194.5 + 1828.5

11.52x = 4023

x = 4023/11.52

x = 349.22°C

Answer:

A) Carbon

Explanation:

the others are wrong its A

Answer:

A) carbon

Explanation:

carbon or simply c has an atomic number of 6 and it has an atomic mass of 12.01 amu. it belongs to group 4a

Answer:

632.7 secs

Explanation:

Equation of the reaction:

Tl^3+ + 3e ------> Tl

If 1F = 96500 C

Q= It

Where;

I= current

t= time

3× 96500 C deposited 204 g of Tl

0.868 × t deposited 0.387 g of Tl

3 × 96500 × 0.387 = 204 × 0.868 × t

t= 3 × 96500 × 0.387/ 204 × 0.868

t= 632.7 secs

The time required for a constant current of 0.868 A to deposit 0.387 g of Tl(III) as Tl(s) is 2689 s

We'll begin by calculating the quantity of electricity needed to deposit 0.387 g of Ti

Ti³⁺ + 3e —> Ti

Recall:

1 mole of Ti = 48 g

1 electron (e) = 96500 C

Thus,

3 electrons = 3 × 96500 = 289500 C

From the balanced equation above,

48 g of Ti was deposited by 289500 C of electricity.

Therefore,

0.387 g of Ti will be deposited by = (0.387 × 289500) / 48 = 2334.09375 C of electricity

Quantity of electricity (Q) = 2334.09375 C

Current (I) = 0.868 A

t = Q / I

t = 2334.09375 / 0.868

Therefore, the time required for the reaction is 2689 s

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Answer:

False

Explanation:

They’re used cause they’re generally harder than pure metals

Alloys are used much more than pure metals because they are generally stronger and less likely to react with air or water...

So I would say false

If we add water to a concentrated acid, then the solution may boil very violently, splashing concentrated acid. If add acid to water, the solution that forms is very dilute and a small amount of heat is released.

When a strong acid is poured into water, it flows down the flask and mixes much better, so no boiling takes place. The addition of water to acid forms an extremely concentrated solution of acid initially. A large amount of heat is released and the solution may boil very violently, splashing concentrated acid out of the beaker and all this because the reaction is exothermic in nature.

The reason this takes place is due to a large amount of energy liberated in the hydration reaction of concentrated ions. Therefore, we add acid to water dropwise for the dilution with constant stirring and not water to acid directly.

If we add water to acid, then an exothermic reaction occurs and the solution may boil very violently. To form the dilute solution of any strong acid, you should add acid to water and the small amount of heat released is not sufficient to vaporize and spatter it.

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Answer: B. Volcanic eruption

Explanation:

A volcano is firmed when molten rocks is formed to the surface of the Earth. Volcanoes release molten rocks, ash, and gases to the Earth's surface.

Volcanoes are agents of change as the eruptions lead to the formation of new landforms and also destroy several things that they come in contact with.

Volcanic eruptions also occurs due to plate tectonics. Other events that happen due to plate tectonics also include earthquakes, and tsunamis.

Answer:B

Explanation:

Answer:

Purple light.

Yellow light.

Explanation:

Answer:

The answer is true

Explanation: Because The law of multiple proportions states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.

Answer:

the answer is D. N

AP3X

According to electronic configuration, there are 3 electrons in the 2p sublevel ,hence the correct option is D.

Electronic configuration is defined as the distribution of electrons that are present in an atom or molecule in  an atomic or molecular orbitals.It describes how each electron moves independently in an orbital.

Knowledge of electronic configuration is important for understanding the structure of periodic table. It helps in understanding the chemical properties of elements.

Elements undergo chemical reactions so as to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in  their ground state and hence are said to be stable.

Thus, the correct option is D.

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Answer:

D.All three graph lines peak over the same few weeks of winter.

Explanation:

took the test

Answer:

opposite

Explanation:

Answer:

opposite

Explanation:

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