An atom's first 2 energy levels are filled and there are 2 electrons in the third energy
level. It's atomic number is:

Answers

Answer 1

Answer:

12

Explanation:

2+8+2=12

atomic no is the No of protons

Answer 2

Answer:

Atomic number is 12.

Explanation:

Atomic number = electrons in filled shells + outermost electrons

= 2 + 8 +2

= 12


Related Questions

draw all the possible isomers of octane​

Answers

Answer:

helps

Explanation:

CH3CH2OH
______ions
in an aqueous solution.
А
forms
B
does not form

Answers

Answer:

When ionic compounds dissolve, they break apart into ions which are then able to conduct a current ( conductivity ). ... Many molecular compounds, such as sugar or ethanol, are nonelectrolytes. When these compounds dissolve in water, they do not produce ions.

Explanation:

Ethanol is an organic compound with an alcoholic functional group and is nonelectrolytes. Ethanol (CH₃CH₂OH) does not form ions in an aqueous solution. Thus, option B is correct.

What are nonelectrolytes?

Nonelectrolytes are substances that do not dissociate readily to yield ions and also are poor conductors of electricity and heat due to a lack of charged ions.

Ethanol is a nonelectrolyte that does not show conductivity and can be dissolved in water without producing ions. They cannot forms ions upon dissociation as covalent bonds are present.

Instead of ions that have covalent compounds that lack the ability to transfer the electron to conduct the electrical charge. Glucose, ethanol, etc. are some examples of a nonelectrolyte.

Therefore, option B. ethanol does not form ions is the correct blank.

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Write the chemical formula for the following:

a. The conjugate acid of amide ion, NH₂-
b. The conjugate base of nitric acid, HNO₃

Answers

Follow the rules of Bronsted Lowry theory

Acids take a HBases donate a H

So

#a

NH_2-

Add a H

Conjugate acid is NH_3

#b

HnO_3

Take a H

Conjugate base is NO_3-

#1

Conjugate acid means one H+ is added

NH_2+H+=NH_3

sw

#2

Conjugate base means donate a H+

HNO_3-H=NO_3-

11. An isotope Q has 18 neutrons a mass number of 34. (a) (i) What is an isotope? An isotope is one of two or C (b) Write its electron arrangement. Mass number=34 Number of neutrons=18 Number of Protons = 34-15-16 (c) To which period and group does Q belong? Protors - Electons - Atomic number Period - Group (d) How does Q form its ion?

Answers

An isotope is an element with the same atomic number but different mass number due to differences in number of neutrons.

electron configuration is 2,8,6.

Belongs to group 6 and period group 3.

It forms an ion by accepting 2 electrons

The elementary reaction 2H2O(g)↽−−⇀2H2(g)+O2(g) proceeds at a certain temperature until the partial pressures of H2O, H2, and O2 reach 0.0900 bar , 0.00100 bar , and 0.00350 bar respectively. What is the value of the equilibrium constant at this temperature?

Answers

Answer:

3.89 ×10^-5

Explanation:

Since they are gaseous reactants, we obtain the equilibrium constant from the given partial pressures;

p(H2O) = 0.0900 bar

p(H2) = 0.00100 bar

p(O2) = 0.00350 bar

The equation of the reaction is;2H2O(g)⇄2H2(g)+O2(g)

Kp= p(H2) . p(O2)/p(H2O)

Kp= 0.00100 × 0.00350/0.0900

Kp= 3.89 ×10^-5

Decide which of the following statements are true and which are false.
True False: Real gas molecules behave most ideally at low temperature and high pressure.
True False: Ideal gas molecules have small volumes and exert weak attractive forces on one another.
True False: At constant temperature, the heavier the gas molecules, the smaller the average velocity.
True False: In order for two separate 1.0 L samples of O2(g) and H2(g) to have the same average velocity, the O2(g) sample must be at a lower temperature than the H
2(g) sample.
True False: At constant temperature, the heavier the gas molecules, the larger the average kinetic energy.
True False: As temperature decreases, the average kinetic energy of a sample of gas molecules decreases.

Answers

Answer:

False

True

True

False

False

True

Explanation:

Ideal behavior of gases is observed at high temperature and low pressure when the gas molecules are isolated from each other.

According to the kinetic theory of gases, gases occupy negligible volume and do not exert significant attractive forces on each other.

The average velocity of gases at constant temperature depends on molecular mass. Heavier molecules possess smaller average velocity than lighter molecules at constant temperature.

At constant temperature, molecules of different gases have the same average kinetic energy but different average velocities since they have different molecular masses. So, the average kinetic energy of gas molecules only depends on temperature.

Identify the true statements regarding hydrogen bonding. Select all that apply. Group of answer choices Hydrogen bonding occurs when a hydrogen atom is covalently bonded to an N, O, or F atom.

Answers

Answer:

True

Explanation:

Hydrogen bonding occurs when hydrogen is covalently bonded to a highly electronegative element such as N, O, or F.

Hydrogen bonding affects several physical properties of molecules in which it occur. For example, the high boiling point of water is caused by intermolecular hydrogen bonding irrespective of the low relative molecular mass of water.

The statement stating the presence of hydrogen bonding between the hydrogen and N, O, and F has been true.

Hydrogen bonding has resulted when the electrostatic interaction has been found in the atoms that have been more electronegative than the Hydrogen atoms.

The electrostatic force helps in attracting the atoms towards the hydrogen and thereby the hydrogen bonding takes place. It has been a weak force present in the molecules. The hydrogen bonding can be easily breakable.

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crassify the given quantities into scalar quantity and vetor quantity ​

Answers

Answer:

where is the quantities?

What minimum mass of HCl in grams would you need to dissolve a 2.2 g iron bar on a
padlock?

Answers

I think your answer should be 2.8 g

2.8 g is the minimum mass of HCl in grams that would you need to dissolve a 2.2 g iron bar on a padlock.

What is dissolution?

When a solute is dissolved in a solvent, a solution is created. Dissolution is the process through which solutes, or dissolved parts, combine to form a solution inside a solvent. In this procedure, the gas, liquid, or solid dissolves inside the original solvent and forms a solution.

In some polymer applications, dissolution is also an issue since it results in swelling, a loss of strength and stiffness, and a change in volume. Whether a chemical process is man-made or natural, dissolution is crucial. Catalysts are tested using dissolution. 2.8 g is the minimum mass of HCl in grams that would you need to dissolve a 2.2 g iron bar on a padlock.

Therefore, 2.8 g is the minimum mass of HCl in grams that would you need to dissolve a 2.2 g iron bar on a padlock.

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A 18.0 L gas cylinder is filled with 6.20 moles of gas. The tank is stored at 33 ∘C . What is the pressure in the tank?
Express your answer to three significant figures and include the appropriate units.

Answers

Answer:

8.65 atm

Explanation:

Using ideal law equation;

PV = nRT

Where;

P = pressure (atm)

V = volume (L)

n = number of moles (mol)

R = gas law constant (Latm/molK)

T = temperature (K)

According to the information given in this question;

V = 18.0 L

n = 6.20 moles

R = 0.0821 Latm/molK

T = 33°C = 33 + 273 = 306K

P = ?

Using PV = nRT

P × 18 = 6.20 × 0.0821 × 306

18P = 155.76

P = 155.76/18

P = 8.65 atm

Calculate the heat change in calories for melting of 0.30 kg of water at 0*C. The
heat of fusion for water is 80 cal/g. The heat of vaporization of water is 540 cal/g.
The specific heat capacity of water is 1.00 cal/g*C.

Answers

Answer: 24 kcal

Explanation:

Given

Mass of water [tex]m=0.3\ kg[/tex]

Temperature of water [tex]T_1=0^{\circ}[/tex]

Heat of fusion [tex]L_f=80\ cal/g[/tex]

Heat of vaporization [tex]L_v=540\ cal/g[/tex]

Specific heat of water [tex]c=1\ cal/g.^{\circ}C[/tex]

Heat require to melt the ice is

[tex]\Rightarrow Q=mL_f\\\Rightarrow Q=0.3\times 1000\times 80\\\Rightarrow Q=24000\ cal\ or\ 24\ kcal[/tex]

Thus, 24 kcal of heat is required to melt 0.3 kg of ice.

Is pre ap chemistry hard in high school?

Answers

If you don't practice enough it's obviously going to be hard but if you practice enough it's going to be a piece of cake so don't think if it's going to be hard or not just think it's going to be worth the try at the very end

Depends on how good u are at studying or taking notes if your good at that you should be fine

A solution has a OH- concentration of 7.7x10-3. What is the pH of this solution?

Answers

Answer:

11.9 pH

Explanation:

First, we need to find pOH

To find that, we use the formula -log[OH]

-log[7.7x10^-3] = 2.11351

To find the pH, we'll use this formula: 14 = pH + pOH

14 = pH + 2.11351

Subtract boths sides by 2.11351

14 = pH + 2.11351

-2.11351  -2.11351

pH = 11.88649

Compounds such as butane and isobutane that have the same molecular formula but differ in the order in which the atoms are connected are called ____________

a. trans isomers

b. cis isomers

c. conventional isomers

d. constitutional isomers​

Answers

Answer:

One compound, called n-butane, where the prefix n- represents normal, has its four carbon atoms bonded in a continuous chain. The other, called isobutane, has a branched chain. Different compounds that have the same molecular formula are called isomers.

Answer:

d. constitutional isomers​

Explanation:

i hope it will help

A 25.0 mL sample of 0.150 M hypochlorous acid is titrated with a 0.150 M NaOH solution. What is the pH at the equivalence point? The Kaof hypochlorous acid is 3.0x10^-8.
a) 10.20
b) 7.00
c) 6.48
d) 7.52
e) 14.52

Answers

Answer:

pH = 10.20

Explanation:

The HClO reacts with NaOH as follows:

HClO + NaOH → H2O + NaClO

Where HClO and NaOH react in a 1:1 reaction.

As the concentration of both reactions is the same and the reaction is 1:1, to reach equivalence point are required the same 25.0mL.

And the NaClO produced decreases its concentration in 2 because the volume is doubled.

The concentration of NaClO is: 0.150M / 2 = 0.075M

The equilibrium of NaClO is:

NaClO(aq) + H2O(l) ⇄ HClO(aq) + OH-(aq)

Where Kb of reaction is 1.0x10⁻¹⁴ / Ka =

1.0x10⁻¹⁴ / 3.0x10⁻⁸ = 3.33x10⁻⁷ = [HClO] [OH-] / [NaClO]

[NaClO] = 0.075M

As both HClO and OH- comes from the same equilibrium,

[HClO] = [OH-] = X

Where X is the reactoin coordinate

Replacing:

3.33x10⁻⁷ = [X] [X] / [0.075M]

2.5x10⁻⁸ = X²

X = 1.58x10⁻⁴M = [OH-]

pOH = -log [OH-]

pOH = 3.80

pH = 14 - pOH

pH = 10.20

Can someone teach me step by step how finding the oxidation number in this problem:

Fe in Fe(CIO2)3​

Answers

Answer:

+3

Explanation:

u see sum of oxidation number in all situations have to be 0

ClO2 =-1

so Fe is +3

Describe a NAMED example of a non-equilibrium system with respect to it’s energetic nature and equilibrium status.

Answers

Answer:

Non-equilibrium thermodynamics is a branch of thermodynamics that deals with physical systems that are not in thermodynamic equilibrium but can be described in terms of variables (non-equilibrium state variables) that represent an extrapolation of the variables used to specify the system in thermodynamic equilibrium.

Explanation:

Which of the following is most likely to happen when a sound wave reflects
off a hard surface? (Assume that neither the source of the sound nor the hard
surface is moving.)
A. A change in speed
B. An echo
C. A change in pitch
D. A beat frequency

Answers

В

an echo is caused by the fact that waves can be reflected by solid surfaces, this is due to the dynamic pattern of rarefactions and air seals near the reflecting surface

5. How many moles are present in 4.20x10^24 atoms of Pb

Answers

Explanation:

[tex]57816 \: moles[/tex]

are present in 4.20x10^24 atoms of Pb

Answer:

7 moles

Explanation:

(4.2*10^24)/(6*10^23)=7

Carboxylic acid derivatives undergo hydrolysis to make carboxylic acids.

a. True
b. False

Answers

Answer:

TRUE

Explanation:

All carboxylic acid derivatives have in common the fact that they undergo hydrolysis (a cleav- age reaction with water) to yield carboxylic acids. with hydroxide ion to yield a carboxylate salt and an alcohol. The carboxylic acid itself is formed when a strong acid is subsequently added to the reaction mixture.

PLS MARK BRAINLIEST

True

All carboxylic acid derivatives have in common the fact that they undergo hydrolysis (a cleav- age reaction with water) to yield carboxylic acids. with hydroxide ion to yield a carboxylate salt and an alcohol. The carboxylic acid itself is formed when a strong acid is subsequently added to the reaction mixture.
PLS MARK BRAINLY PLSSSSSSS

What is the biggest cause of change in Earth's systems?
A. Heat
B. Motion
C. Friction
D. Plate tectonics

Answers

Answer:

heat

Explanation:

because it's the cause of change

Answer:

heat

Explanation:

because it is a natural factor that causes the change in Earth's system

Which of the following chemical equations depicts a balanced ionic equation?
A. 2OH−+Ca2+−>Ca(OH)2
B. OH−+Ca2+−>Ca(OH)2
C. 2OH−+Ca2+−>2Ca(OH)2
D. OH−+2Ca2+−>Ca(OH)2

Answers

Answer:

[tex]{ \sf{A. \: 2OH {}^{ - } _{(aq)} +Ca {}^{2 + } _{(aq)} −>Ca(OH) _{2(s)} }}[/tex]

The chemical equations depict a balanced ionic equation is  2OH−+Ca2+−>Ca(OH)2. option A is correct.

What is the ionic equation?

An ionic equation is a chemical equation in which the electrolytes in an aqueous solution are expressed as dissociated ions. The ions in aqueous solutions are stabilized by ion-dipole interactions with water molecules

Strong acids, strong bases, and soluble ionic compounds (usual salts) exist as dissociated ions in an aqueous solution, and Weak acids and bases and insoluble salts are usually written using their molecular formulas because only a small amount of them dissociates into ions.

Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) → AgCl(s) + Na+(aq) + NO3-(aq) is an ionic equation example.

Therefore, the balanced ionic reaction will be  2OH−+Ca2+−>Ca(OH)2. option A is correct.

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Calculate [H3O+] for pH 1.86. Steps please.

Answers

Answer:

[H₃O⁺] = [H⁺] = 10^-pH = 10⁻¹°⁸⁶ = 0.0138M in [H⁺]  

Explanation:

By definition pH = -log[H⁺] => [H⁺] = 10^-pH = 10⁻¹°⁸⁶ = 0.0138M in [H⁺]

Using your calculator ... I am using a TI-30XA scientific calculator.

=> start by entering the number 1.86 => then press the (+/-) function => this will insert a negative symbol => -1.86,=> next find button with "2nd" printed on face (on some calculators the button is in yellow); press this button to change to 'secondary mode',=> find the symbol (10ˣ) ... the button below this symbol is usually the 'log' button, then press it => the answer of interest will show in the display window. => ...

Depending on the calculator, the answer may show as 0.0138, or  1.38x10⁻², or 1.38E-2 (=1.38 x 10⁻²). It is the user's job to insert dimensional units into answer of interest =>  0.0138M, or  1.38 x 10⁻²M, or 1.38E-2M.

1.38E-2 which is 1.38 x 10⁻².

During the reaction of 2-methyl-2-butanol with the nucleophile-solvent mixture two layers are formed after shaking the reaction for 5 minutes. After removing the aqueous layer with a Pasteur pipette the organic layer is diluted with 1 mL dichloromethane. The organic phase is washed with 1 mL water. Two layers are obtained.

a. Top layer is Aqueous (H20/ H2SO4/NH4CI)
b. Top layer is Organic (CH2Cl2 and product)
c. Bottom layer is Organic (CH2Cl and product)
d. Top layer is Aqueous (H20)

Answers

Answer:

Top layer is Organic (CH2Cl2 and product)

Explanation:

In a solvent mixture, there are usually two phases, the organic phase and the aqueous phase.

It is usual that the organic phase is almost always less dense than the aqueous phase hence the organic phase tend to remain on top of the aqueous phase.

Hence, the top layer is expected to be the organic CH2Cl2 and product.

Consider the reaction: A(aq) + 2B (aq) === C (aq). Initially 1.00 mol A and 1.80 mol B
were placed in a 5.00-liter container. The mole of B at equilibrium was determined to
be 1.00 mol. Calculate K value.
0.060
5.1
25
17
Ugh

Answers

Answer:

17

Explanation:

Step 1: Calculate the needed concentrations

[A]i = 1.00 mol/5.00 L = 0.200 M

[B]i = 1.80 mol/5.00 L = 0.360 M

[B]e = 1.00 mol/5.00 L = 0.200 M

Step 2: Make an ICE chart

        A(aq) + 2 B(aq) ⇄ C(aq)

I       0.200    0.360        0

C        -x           -2x         +x

E     0.200-x  0.360-2x   x

Then,

[B]e = 0.360-2x = 0.200

x = 0.0800

The concentrations at equilibrium are:

[A]e = 0.200-0.0800 = 0.120 M

[B]e = 0.200 M

[C]e = 0.0800 M

Step 3: Calculate the concentration equilibrium constant (K)

K = [C] / [A] × [B]²

K = 0.0800 / 0.120 × 0.200² = 16.6 ≈ 17

Hydrocarbons do not dissolve in concentrated sulfuric acid, but methyl benzoate does. Explain this difference and write an equation showing the ions that are produced.

Answers

Answer:

See explanation

Explanation:

For a substance to dissolve in another, there must be some sort of interaction between the substances.

Recall that like dissolves like. That is, polar substances dissolve polar substances and non polar substances dissolve nonpolar substances.

Hydrocarbons are nonpolar hence they do not dissolve in polar sulphuric acid. Methyl benzoate is polar hence it dissolve in polar sulphuric acid.

The equation showing the ions is depicted in the image attached to this answer.

How many grams of glucose are needed to prepare 144.3 mL of a 1.4%(m/v) glucose solution?

Answers

Answer:

2.0202 grams

Explanation:

1.4% (m/v) glucose solution means: 1.4g glucose/100mL solution.

so ?g glucose = 144.3 mL soln

Now apply the conversion factor, and you have:

?g glucose = 144.3mL soln x (1.4g glucose/100mL soln).

so you have (144.3x1.4/100) g glucose= 2.0202 grams

Which is an example of using an open-ended question to uncover a problem? O a) "Do you have a problem you'd like addressed today?" b) "Is there a problem? C) "What seems to be the problem?" O d) "Can I help you?"

A Single Orbital With Two Lobes At 90°In A Single Plane And A Node In The Center Would Likely Be Found Where?

a.4s


b.4p


c.4d


d. it would not be found in any of these


e.4f

Answers

c i believe it is c

What is a litmus solution? How is it obtained?​

Answers

Litmus solution is generally a purple dye. The solution of Litmus is extracted from lichens. The Litmus solution is used as an indicator to determine the acidic and basic nature of a solution.Lichens plants belonging to the class of Thallophyta. The litmus solution method involves the grinding and crushing of lichens. In order to get the desired litmus solution, such dyes are then introduced to neutral water.

Balance the following reaction:

_______ CO₂ + _______ H₂O + heat ↔ _______ C₆H₁₂O₆ + _______ O₂

Please explain!
*Note: If any of the coefficients are the number one. Please, write "1" in the space. Thanks!

Answers

Answer:

6CO2+6H2O+heat" C6H12O6+6O2

the best way to balance a chemical reaction is to start with balancing the hydrogen followed by the other elements then lastly oxygen.so in this case if you put a 6 in front of carbon dioxide,water and oxygen you will definitely balance it.cause at the first side you have 6 carbons similar to the product,12 oxygen similar to the product and 18 oxygen similar to the products.

I hope this helps

Answer:

Explanation:

I saw this after answering your other question on the same reaction.

To balance the chemical reaction, look at the reactants and products. As O is part of both products, focus on C and H instead.

On the products side, 1 C6H12O6 has 6 C and 12 H. So that requires the same numbers of C and H on the reactant side because of mass conservation.

That gives 6 CO2 and 6 H2O as the reactants. Counting the number of O in the reactants, there are 6*2 + 6 = 18 O. Subtracting the 6 O in C6H12O6, that leaves 12 O so there are 12/2 = 6 O2 in the products.

Combining the numbers above, the balanced equation is:

___6___ CO₂ + ___6___ H₂O + heat ↔ ___1___ C₆H₁₂O₆ + ___6___ O₂

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