Why does the ionization energy change when moving down a group of elements?

The number of valence electrons increases.
The nuclear positive charge increases.
The energy levels are increasing.
The attractive force decreases as the atom gets larger.

Answer:

the answer is stratosphere.

about 90% of ozone is found in the stratosphere.

Answer:

Electromagnet

Explanation:

Answer:

Dmitri Mendeleev

Explanation:

He was a Russian Scientist who decided to reorganize the periodic table after other notable scientists such as Antoine-Laurent Lavoisier had also tried to organize it based on the states of matter of the elements.

Mendeleev reorganized the period in the order of increasing atomic mass although there were some other modifications by modern scientists.

Answer:

255.5cm³

Explanation:

A solution that is 38.08 % by weight has 38.08g of sulfuric acid per 100g of total solution. Thus, mass of solution you need to obtain 125g is:

125g H₂SO₄ × (100g solution / 38.08g H₂SO₄) = 328.3g of solution

As density of the solution is 1.285g / cm³, the volume of 328.3g is:

328.3g × (1cm³ / 1.285g) = 255.5cm³

Answer:

THE NEW VOLUME AT A PRESSURE OF 0.775 atm AND TEMPERATURE OF 18 °C IS 0.397 L

Explanation:

Using the combined gas equation

P1V1/T1 = P2V2/ T2

P1 = 1 atm

VI = 315 mL = 315 / 1000 L = 0.315 L

T1 = 25°C  25 + 273 K = 298 K

P2 = 0.775 atm

T2 = 18 °C = 18 + 273 K = 291 K

V2 = Unknown

Substituting the values into the equation, we obtain:

V2 = P1V1 T2/ P2 T1

V2 = 1 * 0.315 * 291 / 0.775 * 298

V2 = 91.665 / 230.95

V2 = 0.3969 L

The new volume at the given change in conditions is 0.397 L

Answer:

Here's what I get  

Explanation:

Sublimation is the conversion of a solid directly to a gas, without passing through the liquid state.

It occurs when the molecules of a solid have absorbed enough heat (kinetic energy) for some molecules to overcome the attractive forces of their neighbours and escape directly into the vapor phase.

One substance that sublimes at room temperature and pressure is CO₂ (dry ice).

Naphthalene is a substance that sublimes at room temperature and pressure.

Sublimation is defined as a process in which solid converts into gas directly without converting into liquid.

In the sublimation process, the reaction is an endothermic reaction, as the chemical bonds between molecules are broken down in order to release them into the air. Therefore ,the energy is released and so it is an endothermic reaction.

The heat or energy required to change the state from solid to gas is called the enthalpy of sublimation .Generally, it is expressed as KJ/m o l. Sublimation only occurs at pressures and temperatures .

Hence , Naphthalene is a substance that sublimes at room temperature and pressure.

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Answer:

23.6°C

Explanation:

Step 1:

Data obtained from the question. This include the following:

Mass = 0.125kg = 0.125 x 1000 = 125g

Initial temperature (T1) = 22°C

Heat (Q) generated in 4.5mins = 835J

Specific heat capacity (C) of water = 4.184J/g°C

Change in temperature (ΔT) =?

Final temperature (T2) =?

Step 2:

Determination of the change in temperature, ΔT of water.

This can be obtained as shown below:

Q = MCΔT

835 = 125 x 4.184 x ΔT

Divide both side by 125 x 4.184

ΔT = 835 / (125 x 4.184)

ΔT = 1.6°C

Therefore, the change in temperature, ΔT is 1.6°C

Step 3:

Determination of the final temperature of water.

This can be obtained as follow:

Initial temperature (T1) = 22°C

Change in temperature (ΔT) = 1.6°C

Final temperature (T2) =?

Change in temperature (ΔT) = Initial temperature – Final temperature

ΔT = T2 – T1

1.6 = T2 – 22

Collect like terms

T2 = 1.6 + 22

T2 = 23.6°C

Therefore, the final temperature of the water is 23.6°C.

Answer:

please give more clarification

Answer:

Evaporation, Radiation

Explanation:

Evaporation of water from your skin if it is wet (sweating). ...

Radiation (similar to heat leaving a woodstove).

Answer:

first answer

Explanation:

atomic number of bromine is 35

[tex]1{s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 3 {d}^{10} 4 {s}^{2} 4 {p}^{5} [/tex]

Answer:

1s22s22p63s23p64s23d104p5

Explanation:

;)

Answer:

Explanation:

Pv = n RT

P =7.65, T= 310K, for glucose n = moles= weight/molar mass= weight/180, R is gas constant

7.65* V =W/180 *0.0821 * 310

w/v= 7.65*180/0.0821*310 = 1377/25.45 = 54.10 =5.4%

Answer:

The angular alignment is 90 degrees

Explanation:

The neap tide is a type of tide which occurs around seven days after a spring tide. This type of tide happens twice every month.

The tide is usually moderate and it exists when the sun and moon are usually at right angles to each other when it occurs. A right angle is also known as 90 degrees which validates the tide occurring at an angle 90.

Answer:

Two moles.

Explanation:

Sulphuric (sulfuric) acid [tex]\rm H_2SO_4[/tex] is a diprotic acid. When one mole of [tex]\rm H_2SO_4[/tex] molecules dissolve in water, two moles of [tex]\rm H^{+}[/tex] ions would be produced.

[tex]\rm H_2SO_4 \to 2\, H^{+} + {SO_4}^{2-}[/tex].

On the other hand, sodium hydroxide [tex]\rm NaOH[/tex] is a monoprotic base. When one mole of [tex]\rm NaOH[/tex] formula units dissolve in water, only one mole of hydroxide ions [tex]\rm OH^{-}[/tex] would be produced.

[tex]\rm NaOH \to Na^{+} + OH^{-}[/tex].

Note that [tex]\rm H^{+}[/tex] and [tex]\rm OH^{-}[/tex] react at a one-to-one ratio:

[tex]\rm H^{+} + OH^{-} \to H_2O[/tex].

As a result, it would take [tex]2\; \rm mol[/tex] of [tex]\rm OH^{-}[/tex] to react with the [tex]\rm 2\; mol[/tex] of [tex]\rm H^{+}[/tex] that was released when [tex]1\; \rm mol[/tex] of [tex]\rm H_2SO_4[/tex] is dissolved in water. Since one mole of [tex]\rm NaOH[/tex] formula units could produce only one mole of [tex]\rm OH^{-}[/tex], it would take [tex]\rm 2\; mol[/tex] of [tex]\rm NaOH[/tex] formula units to produce that [tex]2\; \rm mol[/tex] of [tex]\rm OH^{-}[/tex] for reacting with [tex]1\; \rm mol[/tex] of [tex]\rm H_2SO_4[/tex].

Answer:

90.2%

Explanation:

% yield = actual yield/ theoretical yield * 100%

% yield = (312/346)*100% = 90.2%

Answer:

. A homogeneous mixture of a solid in a gas

Given question is incomplete. The complete question is as follows.

Balance the following equation:

[tex]H_3PO_4 + Ca(OH)_2 \rightarrow Ca(H_2PO_4)_2 + H_2O[/tex]

Answer: The balanced chemical equation is as follows.

[tex]2H_3PO_4 + Ca(OH)_2 \rightarrow Ca(H_2PO_4)_2 + 2H_2O[/tex]

Explanation:

When a chemical equation contains same number of atoms on both reactant and product side then this equation is known as balanced equation.

For example, [tex]H_3PO_4 + Ca(OH)_2 \rightarrow Ca(H_2PO_4)_2 + H_2O[/tex]

Number of atoms on reactant side:

H = 5

P = 1

O = 6

Ca = 1

Number of atoms on product side:

H = 6

P = 2

O = 9

Ca = 1

In order to balance this equation, we will multiply [tex]H_3PO_4[/tex] by 2 on reactant side and we will multiply [tex]H_2O[/tex] by 2 on product side. Hence, the balanced chemical equation is as follows.

[tex]2H_3PO_4 + Ca(OH)_2 \rightarrow Ca(H_2PO_4)_2 + 2H_2O[/tex]

Answer: C.) Xe

Explanation: To figure out the answer go to the Noble Gas Family and count down 5 elements.

According to the electronic configuration the symbol which would be included in the noble gas notation for an element that had valence electrons in the 5 s subshell is xenon  .

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

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

Elements undergo chemical reactions in order 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 ground state and hence are said to be stable.

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Answer:

it all really depends on the superiors of the government. everyone's so corrupt with their views these days, and let personal opinions rules over what the people want. as a latina, i think we should keep fighting and protesting till we get what we really deserve.

Explanation:

Answer:

no

Explanation:

this experiment could not be replicated, because there are no specific measurements. the details would not be the same because it does not include the type of paper used nor the diameter, width or length. A guess of the measurements would be the only way to replicate this experiment but other then that, no you cannot.

Answer:

a

2.0 M

Explanation:

divide 6by 3

formula :  molarity=moles divided by volume of solutions

Answer:

the answer is A

Explanation:

Forces are the intermolecular interaction between the matter. Forces present in a solid are strongest. Thus, option A is correct.

The matter is any substance that occupies a volume. Matter can be a solid, gas, or liquid. The solid phase particles are tightly closed to each other making the force strong.

The particles of liquids that are not too compact are a little free and in gases, the particles are very free, which makes the bonding and the force the weakest.

Therefore, option A. the solids have the strongest intermolecular bonding.

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Answer:

There are no oxygen

Explanation:

Hydro is used when naming hydrogen compound and oxo is used when naming oxygen compound

Answer:

changing while growing

Explanation:

Answer: the answer is a

Answer:

a) [COHNH₂] = 0.001 mol/L, [NH₃] = [CO] = 0.085 mol/L

b) 5.59 atm

Explanation:

a) The decomposition reaction of formamide is the following:

COHNH₂(d)  ⇆  NH₃(g) + CO(g)    

The equilibrium constant of the reaction above is:

[tex]K_{c} = \frac{[NH_{3}][CO]}{[COHNH_{2}]} = 4.84 (400 K)[/tex]

The initial concentration of formamide is:

[tex] C_{COHNH_{2}} = \frac{\eta}{V} = \frac{0.186 moles}{2.16 L} = 0.086 mol/L [/tex]

Where: η is the number of moles and V is the volume

Now, in the equilibrium the concentration of all species is:

COHNH₂(d)  ⇆  NH₃(g) + CO(g)  

0.086 - x              x             x

[tex] K_{c} = \frac{[NH_{3}][CO]}{[COHNH_{2}]} = \frac{x*x}{0.086 - x} [/tex]  

[tex] 4.84*(0.086 - x) -x^{2} = 0 [/tex]

By solving the above equation for x we have:

x = 0.085 mol/L = [NH₃] = [CO]

[COHNH₂] = 0.086 - 0.085 = 0.001 mol/L

Therefore, the concentrations of all species present at equilibrium at 400 K is [NH₃] = [CO] = 0.085 mol/L and [COHNH₂] = 0.001 mol/L.

b) To find the total pressure in the container we need to find first the constant Kp as follows:

[tex] K_{p} = K_{c}*RT^{\Delta n} [/tex]

Where R is the gas constant = 0.082 Latm/(Kmol), T is the temperature = 400 K and Δn = 1

[tex] K_{p} = K_{c}*RT^{\Delta n} = 4.84*(0.082*400)^{1} = 158.8 [/tex]

Now, the total pressure is:

[tex] p_{T} = p_{COHNH_{2}} + p_{NH_{3}} + p_{CO} [/tex]

The pressure of COHNH₂ can be found using Ideal Gas Law:

[tex] P = \frac{nRT}{V} = \frac{0.186 moles*0.082 L*atm/(K*mol)*400 K}{2.16 L} = 2.82 atm [/tex]

Using the equilibrium constant we can find the pressure of NH₃ and CO:

COHNH₂(d)  ⇆  NH₃(g) + CO(g)  

2.82 - x              x             x

[tex] K_{p} = \frac{P_{NH_{3}}*P_{CO}}{P_{COHNH_{2}}} [/tex]

[tex] 158.8*(2.82 - x) - x^{2} = 0 [/tex]

By solving the above equation for x we have:

[tex] x = P_{NH_{3}} = P_{CO} = 2.77 atm [/tex]

[tex] P_{COHNH_{2}} = 2.82 - 2.77 = 0.05 atm [/tex]

Thus, the total pressure is:

[tex] p_{T} = p_{COHNH_{2}} + p_{NH_{3}} + p_{CO} = (0.05 + 2.77 + 2.77) atm = 5.59 atm [/tex]

Hence, the total pressure in the container at equilibrium is 5.59 atm.

I hope it helps you!

Answer:

C) Liquids and gases

Explanation:

The correct answer would be liquids and gases.

The molecules of liquids and gases move randomly when held in a container. The random movement causes a collision between the molecules of the liquids/gases and between the walls of the container, creating pressure in the process. This is unlike the molecules of solids that vibrate about fixed positions.

Hence, the correct option is C.

Answer:

N = n× l

N = number of entities

n= moles

l = Avogadro's constant = 6.023 × 10^23

3.01 × 10^ 23 = n * 6.023 × 10^23

n = 3.01 × 10^23/6.023 × 10^23

n= 0.5moles

Molar mass = mass/ number of moles

Molar mass = 56

mass = 56 × 0.5

= 28g

Hope this helps.

Answer:

gasoline

Explanation:

Answer:

your answer will be photosynthesis

Explanation:

Answer:

The chemical equation needs to be balanced so that it follows the law of conservation of mass.

Explanation:

Explanation:

the chemical equation needs to be balance so that it follows the law of conservation of mass. a balance chemical equation occurs when the number of the different atoms of elements to the reactants side is equal to that of the product side. balancing chemical equation is a process of trial and error .

Answer:

A.Scientists use genes to explain why evolution happens.

Explanation:

:)