Select the atoms that belong to the same element.

Answer:

18.4 kPa

Explanation:

Step 1: Given data

Step 2: Calculate the final pressure of the gas

If we assume the gas behaves as an ideal gas, we can calculate its final volume using Boyle's law.

P₁ × V₁ = P₂ × V₂

P₂ = P₁ × V₁/V₂

P₂ = 90.1 kPa × 10.0 L/49.0 L

P₂ = 18.4 kPa

Answer:

A. Chloroplast

Explanation:

Answer: Percentage Compositon Of A in the sample= 28.99%

Explanation:

First we calculate the Peak area.

Because each peak is consdered like a triangle in a Chromatogram, The Area of the peak is calculated as  = height x half height of the width

Area of Pea A= 25.1 mm X 4.6mm=115.46mm2

Area of Peak B= 14.5mm x 4.4mm=63.8mm2

Area of PeaK C=  37.1mm x5.9mm =218.89mm2

Total Peak Area=  398.15mm2

Percentage Area of Peak A =  Area of Peak A/Total Peak Area x 100

= 115.46 / 398.15  x 100

=0.2899 x 100

=28.99%

Percentage Compositon Of A = 28.99%

Answer:

B. A few elements can combine to form a compound

Explanation:

Source:  Tro Nivaldo J.. Principles of Chemistry (p. G-4). Pearson Education. Kindle Edition.

Answer:

.A few elements can combine to form a compound

Explanation:

The image having the complete question is attached to this answer.

Answer:

Ga

Explanation:

In order to answer this question well, we must have a good enough knowledge of the periodic table.

We know that the elements in group 3A or group 13 of the periodic table have three valence electrons in their outermost shell.

We just have to look out among the options to notice if there is any member of group 3A or 13.

Gallium is a member of this group. Hence the answer above.

Answer:

8.6 mol

Explanation:

number of moles = molar concentration x volume in litre

number of moles = 2.33 M x 3.70 L = 8.6 mol

Answer:

B. Fluorine (F) element easily gains one electron to for a negative ion.

Answer:

the pulpy acidic fluid which passes from the stomach to the small intestine, consisting of gastric juices and partly digested food.

Answer

Cold Climates

Explanation:

It can go slow

Answer:

Mass of Cl₂  = 887.5 g

Mass of Na = 575 g

Explanation:

Given data;

Number of moles of sodium chloride produced = 25.0 mol

Mass of Na required = ?

Mass of Cl₂ required = ?

Solution:

Chemical equation:

2Na  +   Cl₂    →      2NaCl

now we will compare the moles of sodium chloride with both reactant.

                      NaCl         :          Na

                         2            :           2

                      25.0         :         25.0

                    NaCl          :          Cl₂

                       2             :           1

                      25.0        :          1/2 ×25.0 = 12.5 mol

Mass of Na:

Mass = number of moles × molar mass

Mass = 25.0 mol × 23 g/mol

Mass = 575 g

Mass of Cl₂:

Mass = number of moles × molar mass

Mass = 12.5 mol × 71 g/mol

Mass = 887.5 g

Answer:

B

Explanation:

I took the test

Answer:

The correct answer is B

Explanation:

Answer: A = atomic number = 12

Explanation: A (atomic number) defines the chemical element. It is the numbervof protons or electrons. Neutron numbers may vary, produving isotopes of differing atomic mass. This isotope has atomic mass 28. The atomic number 12 = carbon. C28 does not really exist. If it could be produced it would be radioactive with an almost zero halflife.

Answer:

Mass = 255 g

Explanation:

Given data:

Number of moles of nitrogen = 7.5 mol

Mass of ammonia formed = ?

Solution:

Chemical equation:

3H₂ + N₂      →    2NH₃

Now we will compare the moles of nitrogen and ammonia.

             N₂         :        NH₃

               1          :         2

              7.5       :       2/1×7.5 = 15

Mass of ammonia:

Mass = number of moles × molar mass

Mass = 15 mol × 17 g/mol

Mass = 255 g

Answer:

A4

B1

C3

D2

Explanation:

A4: dispersion forces occur in everything as it is variations in the electron cloud.  They are very weak and are the only intermolecular force in a non-polar molecule such as CH4.

B1: Dipole Dipole forces occur between polar molecules.  The polarity of the molecule creates a dipole which can attract each other.  they are stronger then dispersion forces.  CBr2Cl2 is a polar molecule.

C3: hydrogen bonding is a special type of dipole-dipole force and are pretty strong.  They can only occur between H-N, H-O, and H-F bonds. NH3 has N-H bonds.

D2: ion dipole forces occur between a polar molecule and ions.  They mainly occur when charged species (ions) are in a polar solvent but there are likely less common examples.

I hope this helps.  Let me know if anything is unclear.

Answer:

It will remain the same.

Explanation:

A buffer solution is a kind of solution that has resistance for changes in the pH of a solution. It is a solution of weak acid and conjugate base or it may be otherwise.

H^+ + A^- <====================> HA.

Buffer solution aids in stabilizing pH and an example of a buffer solution is the human blood.

The higher the concentration, the lower the ka and vice versa. Thus, when 0.4M is being used instead of 0.2M the pH will be the same because when dealing with buffer solution, it is all about the value of (salt) / (acid) rather than on the molarity of one specie alone.

Answer: Condensation

Explanation: Condensation forms clouds when water vapor in the air cools down into water and crystals.

Answer:

The 3rd one " C " because it surrounds the nucleus it's not known the inside

An electron is found in the space surrounding the nucleus.

An electron is a sub-atomic particle which is found in the extra-nuclear part of an atom. They are found revolving int the shells which surround the nucleus.It carries a negative charge of  minus 1 .

They are the elementary particles as they do not  have known components or structure. It has a mass which is approximately equal 1/1836 th that of proton.No two electrons can occupy the same  quantum state according to the Pauli exclusion principle.

As all elementary particles, it too does possess both particle and wave characteristics. They can collide with each other and cause diffraction . Wave properties of electrons are easier to observe  with aid of experiments, because of lower mass and longer de Broglie wavelength.

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Answer:

The formula of the magnesium halide is MgF₂

Explanation:

All halides, X, produce a salt with Mg with the formula:

MgX₂

-There are 2 moles of the halide ion per mole of Mg-

With the mass of the MgSO₄ we can find moles of magnesium sulfate  = Moles Mg.

With moles of Mg we can know the moles of the halide -1 mole Mg = 2 moles of Halide-

And we can find the mass of Mg in the 0.0776g sample. Subtracting we can find the mass of the halide and, with the mass and moles of the halide we can find its molecular weight and its identity:

Moles MgSO₄ -Molar mass: 120.366g/mol- = Moles Mg:

0.150g * (1mol / 120.366g) = 1.2462x10⁻³ moles Mg

Moles halide:

1.2462x10⁻³ moles Mg * 2 = 2.4924x10⁻³ moles Halide

Mass Mg -Molar mass: 24.305g/mol:

1.2462x10⁻³ moles Mg * (24.305g / mol) = 0.0303g Mg

Mass halide:

0.0776g - 0.0303g Mg = 0.0473g

Molecular weight of the halide:

0.0473g / 2.4924x10⁻³ moles =

18.98g/mol

This molecular weight is the molecular weight of Fluoride ion, F⁻,

Answer:

1/5g/ml

Explanation:

D=m/v

D=5.0/25

D=1/5g/ml

Answer:

When it is absorbed, it is converted into heat energy, and the object heats up.

Explanation:

When the photon is absorbed, it is released as heat energy.

Howmuch woodwouldawoodchuckchuckifawoodchuckcouldchuckwoodwoodchuckcouldchuckwoodwoodchuck

Answer:

7 bcs atomic number of atom is its number of proton.

hope it helps.

Answer:

chemical energy

Explanation:

chemical energy is potential energy

The energy associated with the relative positions of electrons and nuclei in atoms and molecules is called thermal energy.

Generally, the energy possessed by an object due to its position is known as potential energy of the object while the energy possessed by an object due to its motion is called kinetic energy.

However, thermal energy describes the energy that is associated with the relative positions of electrons and nuclei in atoms and molecules.

Thus, we can conclude that the energy associated with the relative positions of electrons and nuclei in atoms and molecules is called thermal energy.

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Answer:

12.5

Explanation:

Step 1: Write the balanced equation

2 NO₂(g) ⇄ N₂O₄(g)

Since the reaction takes place in a 1.00 L vessel, the initial concentration of NO₂ is 0.0300 M and the concentration at equilibrium of N₂O₄ is 0.00500 M.

Step 2: Make an ICE chart

        2 NO₂(g) ⇄ N₂O₄(g)

I          0.0300        0

C           -2x            +x

E     0.0300-2x        x

Step 3: Find the value of x

Since [N₂O₄]eq = 0.00500 M, x = 0.00500

Step 4: Calculate the concentrations at equilibrium

[NO₂] = 0.0300-2(0.00500) = 0.0200 M

[N₂O₄] = 0.00500 M

Step 5: Calculate the concentration equilibrium constant (Kc)

Kc = [N₂O₄]/[NO₂]²

Kc = 0.00500/0.0200²

Kc = 12.5

Answer:

A. X-rays have a higher frequency and carry more energy than visible light.

Explanation:

Answer:

A. X-rays have a higher frequency and carry more energy than visible light

Explanation:

Both x-rays and visible light are electromagnetic waves.

The amount of energy carried by an electromagnetic wave depends on the frequency of the wave. The frequency of x-rays is greater than that of visible light, so the energy carried by x-rays is also greater than that of visible light. The high frequency of x-rays allows them to penetrate skin, but they are absorbed by bone, which allows an image of the bone to be produced.

Answer:

1-decanethiol on top layer and water on the bottom layer.

Explanation:

Hello!

In this case, since long-chained alcohols have a predominant nonpolar section in the molecule, we understand they are largely insoluble in water, also because their densities tend to be less than that of the water, which means they act as a light phase and water the heavy phase.

In such a way, when mixing equal volumes of 1-decanethiol and water in a separatory funnel, a phase splitting is evidenced and the alcohol remains on the top layer because of its lower density.

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Answer:

The higher up an object is the greater its gravitational potential energy. ... As most of this GPE gets changed into kinetic energy, the higher up the object starts from the faster it will be falling when it hits the ground. So a change in gravitational potential energy depends on the height an object moves through.

Answer:

K < Si < O < H

Explanation:

The ionization energy is regarded to be the amount of energy required to remove an electron in an atom from its ground state. The factor that determines the Ionization energy atomic radius. This is because the larger the atomic radius, the smaller the Ionization energy because of the shielding effect or screening effect of the inner shell electrons.  Across the period, the ionization energy increases progressively from left to right due to decreasing atomic radii caused by the increased nuclear charge. Also, down the period the ionization energy decreases because of increasing atomic radii and increasing shielding effect or screening effect of the inner shell electrons.

So, the increasing order of Ionization energy of the given elements are:

K < Si < O < H

Answer:

density = mass / volume

mass of iron = 9.3g

volume of iron = 29.78ml - 28.00ml = 1.78 ml

density of iron = 9.3 / 1.78 = 5.22471910112 = 5.0

Explanation: