The successive ionization energies for a given element are listed. How many valence electrons does it have?

Answer:

Number of unpaired electrons

Explanation:

We know that for the compounds listed, the nature of the electrons in the d orbitals affects their interaction with an applied magnetic field.

If there are unpaired d electrons present, the compound is paramagnetic and is more strongly attracted to a magnetic field.

Similarly, if there are paired d electrons, the compound is diamagnetic and is less strongly attracted to a magnetic field.

The  molarity of the HNO₃ solution : 0.212 M

Given

62.4 mL HNO₃

56.25 mL of a 0.235 M  KOH

Required

Molarity HNO₃

Solution

Titration formula

M₁V₁n₁=M₂V₂n₂

1= HNO₃, 2 = KOH

n = acid base valence (amount of H⁺/OH⁻ released,for HNO₃ and KOH = 1)

Input the value :

M₁ x 62.4 x 1 = 0.235 x 56.25 x 1

[tex]\tt M_1=\dfrac{0.235\times 56.25\times 1}{62.4\times 1}\\\\M_1=0.212[/tex]

Answer:

0.212

Explanation:

Answer:

They are all mixture

Explanation:

last option

Answer:

V = 11.2L are produced

Explanation:

... Sample of 27g of pure aluminium, 3added to 333 mL of 3.0 M HCl..

Based on the chemical reaction:

2Al(s) + 6HCl(aq) → 2AlC₃(aq) + 3H₂(g)

Where 3 moles of hydrogen are produced when 6 moles of hydrochloric acid reacts with 2 moles of Al.

To solve this question, we need to determine limiting reactant converting each reactant to moles. With limiting reactant and the chemical reaction we can find moles of hydrogen and its volume at STP (T=273.15K; P=1atm), thus:

Moles Al-Molar mass: 26.98g/mol-:

27g * (1mol / 26.98g) = 1mol of Al

Moles HCl:

333mL = 0.333L * (3mol/L) = 1mol HCl

For a complete reaction of 1 mole of HCl are required:

1mol HCl * (2mol Al / 6mol HCl) = 0.333 moles of Al. As there is 1 mole of Al, Al is in excess and HCl is limiting reactant.

Moles of Hydrogen produced are:

1mol HCl * (3 moles H₂ / 6 mol HCl) = 0.5moles H₂ are produced.

Using ideal gas law:

PV = nRT

V = nRT/P

Where V is volume

n are moles: 0.5mol

R is gas constant: 0.082atmL/molK

T is absolute temperature: 273.15K

P is pressure: 1atm.

Solving for V:

V = 0.5mol*0.082atmL/molK*273.15K / 1atm

Answer:

C Group 11

Explanation:

Group 11, by modern IUPAC numbering, is a group of chemical elements in the periodic table, consisting of copper (Cu), silver (Ag), and gold (Au).

These elements show highest electrical conductivity.

Answer:

C Group 11

Explanation:

Group 11, by modern IUPAC numbering, is a group of chemical elements in the periodic table, consisting of copper (Cu), silver (Ag), and gold (Au).

These elements show highest electrical conductivity.

Explanation:

Answer:

2 atm

Explanation:

The symbol 'atm' is used for pressure. Hence, the symbol used to indicate the pressure at which a chemical reaction is carried out can be, 2 atm.

Answer:

26

Explanation:

The number of electrons and protons are equal.

Answer:

Explanation:

From the combustion of carbon, the reactions occurring in limited oxygen conditions are:

[tex]C(graphite) + \dfrac{1}{2}O_{2(g)} \to CO_{(g)}[/tex]  

[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]  

If it occurs in excess, then any leftover CO changes to CO2. i.e.

[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]   ---- (1)

[tex]CO_{(g)} + \dfrac{1}{2}O_{(g)} \to CO_{2(g)}[/tex]          ----- (2)

From (1), the enthalpy change is:

[tex]\Delta H_{rxn1} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{f C(graphite)}+ \Delta H^0_{fCO_2(g)}[/tex]

[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol -(0+0)[/tex]

[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol[/tex]

From (2), the enthalpy change is:

[tex]\Delta_{rxn2} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{fCO(g)} + \dfrac{1}{2} \Delta H^0_{fO_2(g)})[/tex]

[tex]\Delta_{rxn2} = -393.5 \ kJ/mol -(-110.5 + \dfrac{1}{2}(0))[/tex]

[tex]\Delta_{rxn2} = -283.0 \ kJ/mol[/tex]

Subtracting (2) from (1), we get:

[tex]C(graphite) + O_{2(g)} \to CO_{2(g)} \ \ \ \Delta H_{rxn} = -393.5 \ kJ/mol}[/tex]

[tex]CO_{(g)} + \dfrac{1}{2} O_2(g) \to CO_{2(g)}} \ \ \ \Delta H _{rxn2} = -283.0 \ kJ/mol[/tex]

[tex]C(graphite) + O_{2(g)} \to CO (g) + \dfrac{1}{2}O_{2(g)} \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]

[tex]C(graphite) + \dfrac{1}{2} O_{2(g)} \to CO (g) \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]

The enthalpy change ΔH of the reaction = -110.5 kJ/mol

Answer: The Correct Answer is Choice B.

Explanation: I just took the quiz.

ANSWER:

B. Electrons have transferred from one atom to another.

EXPLANATION:

An oxidation-reduction (redox) reaction is a reaction which involves the change in oxidation number of the atoms involved. Since the oxidation number changes, this means that one atom has to lose electrons and another has to accept electrons. The reactant that loses electrons is called REDUCING AGENT while the reactant that gains electrons is called OXIDIZING AGENT.

For example, in a reaction between iron and oxygen as follows:

4Fe+ 3O2→2Fe2O3

Iron is reduced from +2 to 0 because it accepts electrons from oxygen while oxygen is oxidized from -2 to 0 because it transfers electrons to iron.

Hence, a redox reaction can be identified by the transfer of electrons from one atom to another.

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Answer:

b. a type of gas is evolved ( hydrogen gas )

Answer:

Lithosphere

Explanation:

The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure. It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below.

MARK ME AS BRAINLIEST PLS

Answer:

23 atoms. I hope this helped u

Explanation:

Answer:

D

Explanation:

Answer:

Keep the world safe and clean

Explanation:

safety = keep people inline and help them from making bad decisions

clean = keep the world from being polluted or trashy

Astronomy deals with the study of celestial objects such as moon, stars, sun, planets, etc.

Safety is the art of being protected from danger

Recycling is the process of waste conversion. That is, useful materials are generated from wastes.

Astronomers, in their exploration of extraterrestrial bodies, need to ensure that proper measures are taken to ensure their safety in these locations. Unhealthy practices such as deforestation and indiscriminate waste disposal may cause environmental hazards such as global warming. This is a threat to the atmosphere.

Therefore, wastes have to be converted to reusable products to discourage indiscriminate disposals. Hence the importance of the terms "safety" and "recycling" in astronomy.

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Answer:  B

a chemical change, because a gas is being formed

Explanation:

Answer:

B

Mark Brainliest please

Explanation:

Answer:

m=621.54g

Explanation:

number of moles= mass of H2O/molar mass of H2O

n=m/mm

make mass the subject of the formula

m=n*mm

find molar mass of water

H2O=1(16)+2(1)

mm= 18.0g/mol. n=34.53mol

hence, m=34.53mol*18.0g/mol

m=621.54g

Answer: 1 mole of strontium, 2 moles of hydrogen, 2 moles of carbon, 6 moles of O

Explanation: i think i’m not sure

A mole corresponds to the mass of a substance that contains particles of the substance.

The concept of moles are used in various ways:-

According to the question, the formula required is:-

[tex]n=\frac{Number\ of\ molecules}{na}[/tex]

The Na is defined as the Avogadro constant is the proportionality factor that relates the number of constituent particles in a sample with the amount of substance in that sample.

According to the question, the compound is [tex]Sr(HCO_{3})_{2}[/tex].

Hence the correct option is 2, that is 1 mole of strontium, 2 moles of hydrogen, 2 moles of carbon, 6 moles of oxygen.

For more information, refer to the link:-

https://brainly.com/question/19968870

Answer:

Silicon has 14 protons, 14 neutrons, and 14 electrons.

Explanation:

The question is incomplete, the complete question is;

The compound magnesium nitrate is a strong electrolyte. Write the reaction when magnesium nitrate is put into water:

Answer:

Mg(NO3)2(s)--------->Mg^2+(aq) + 2NO3^-(aq)

Explanation:

When we say that a compound is a strong electrolyte, we mean that that the compound dissociates completely in solution to form its ions.

This means that all strong electrolytes attain 100% dissociation of the solid in water according to its stoichiometric equation.

For magnesium nitrate, the reaction equation is;

Mg(NO3)2(s)--------->Mg^2+(aq) + 2NO3^-(aq)

Answer:

6. false.  

chemical energy to heat and mechanical. Mechanical that runs the factory in the photo, and Heat energy that rises up in the atmosphere to join the other carbon

molecules in the air. 7. True. The arrow letter A is the transfer of solar power

from the sun, to a chemical reaction to produce food for the plant, which is

called photosynthesis. The leaves in the plant has chlorophyll that absorbs light

energy and transforms it to food.8. The answer would be letter C and F. C because It is

during the burning of the fossil fuels that the carbon dioxide is release into

the atmosphere. When burning the fossil fuels the carbon that was inside the

fossils is released. This also happens with diesel and other forms of natural

gas. While, F is because plant

respiration releases some of the carbon remains of the photosynthesis. While

plants do absorb carbon dioxide, part of their end product also includes reformed

carbon dioxide. Most of the other processes in the phot uses carbon or absorbs

carbon dioxide to aid their sustenance.9. A carbon cycle for living things would be A or B to F

wherein the plants absorb carbon dioxide to aid their production of food, and

then releasing carbon dioxide again as a by product of their food production.

This also happen to aquatic plants.An example of a non-living carbon cycle would be, D or E to

C. This would be the absorption of the carbon on our sea waters or to our soil,

this then gets trapped in there until it is release like through the forms of

fossil fuel burning.10. The law of conservation of mass and energy states that

matter can neither be created nor destroyed, this is very much evident in the

carbon cycle. Because the carbon from the light energy from the sun, or in our

atmosphere, ends up back to our atmosphere just to continue its cycle. The fact

that the carbon cycle is a cycle not just a linear equation proves that energy

can neither be created nor destroyed.

Explanation:

Answer:

1)A mixture that is easily separated, the components are different sixes and unevenly mixed.

Explanation:

Mixtures are impure substances with usually indefinite composition. Their constituents often retains their identities. They can easily be separated into constituents by physical methods.

Homogenous mixtures have their constituents existing in only one phase.

Heterogeneous mixtures have their constituents existing in at least two different phases.

The equations that show a precipitation reaction would be [tex]MgSO_4(aq) + CaCl_2(aq) --- > MgCl_2(aq) + CaSO_4(s)[/tex], [tex]FeCl_2(aq) + Na_2CO_3(aq) --- > FeCO_3(s) + 2NaCl(aq)[/tex], and [tex]2AgNO_3(aq) + Na_2S(aq) --- > Ag_2S(s) + 2NaNO_3(aq)[/tex]

It is a reaction in which two soluble salts react in aqueous solutions to form one soluble and one insoluble salt.

Thus, all the equations with an insoluble salt as one of the products will qualify as precipitation reactions. The insoluble is designated as (s).

Hence, the following are precipitation reactions:

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Answer:

Here is your answer......

Answer:

Explanation:

Energy

Answer:

0.2g

Explanation:

mass=mole/molar mass

molar mass of oxygen is 32

6.06/32=0.19 or 0.2 units=grams

it might look like it has disappeared, but in fact it has just mixed with the water to make a transparent