Why did the model of the atom change?
A. New materials became available to build better models.
B. The structure of atoms changed over time.
C. Scientists did not like the original model.
D. Experiments provided new evidence about the atom.

Answers

Answer 1
D. Experiments provided new evidence about the atom, I think, sorry if I’m wrong

Related Questions

Given 32.0 g of water, if we see a temperature change from 25.0°C to 20.0°C, then how much heat energy (q) is transferred from the water?

(The specific heat of water is 4.184 J/g°C )

Answers

Answer:

Q = 669.44 J

Explanation:

Given that,

Mass of water, m = 32 g

The temperature change from 25.0°C to 20.0°C.

We need to find the amount of heat energy transferred. Let it is Q. We know that,

[tex]Q=mc\Delta T[/tex]

Where

c is the specific heat of water

Put all the values,

[tex]Q=32\times 4.184 \times (20-25)\\Q=669.44\ J[/tex]

So, 669.44 J of heat energy is transferred from the water.

A student went to the cafeteria and bought iced tea. He then proceeded to add more sugar to his iced tea. In this solution, the iced tea was the __________ and the sugar was the ____________.

Answers

The iced tea was the solvent and the sugar was the solute

A student enters the canteen and buys iced tea. He then goes on to add more sugar to his iced tea. In this solution, iced tea is the solvent and sugar is the solute.

Silver nitrate, AgNO3, reacts with ferric chloride, FeCl3, to give silver chloride, AgCl, and ferric nitrate, Fe(NO3)3. In a particular experiment, it was planned to mix a solution containing 25.0 g of AgNO3 with another solution containing 45.0 grams of FeCl3. Write the chemical equation for the reaction.​

Answers

Answer:

[tex]\mathbf{FeCl_3 + AgNO_3 \to 3 AgCl+Fe(NO_3)_3}[/tex]

Explanation:

From the given question,

The chemical equation is:

[tex]\mathbf{FeCl_3 + AgNO_3 \to 3 AgCl+Fe(NO_3)_3}[/tex]

We are given that:

mass of [tex]FeCl_3[/tex] = 45 g

number of moles of [tex]FeCl_3[/tex]  = 45 g/162.2 g/mol

= 0.28 mol

mass of [tex]AgNO_3[/tex] = 25g

number of moles of [tex]AgNO_3[/tex]  = 25/169.87

= 0.147 mol

From the given equation 1 mole of [tex]FeCl_3[/tex] is required to make 3 mole of [tex]AgNO_3[/tex]  

0.28 mole of [tex]FeCl_3[/tex] = 0.28 × 3 = 0.84 mol of [tex]AgNO_3[/tex]  

Here [tex]AgNO_3[/tex]  is the limiting reagent.

Thus,

3 mole of [tex]AgNO_3[/tex]  = 3 moles of AgCl

0.147 mole of [tex]AgNO_3[/tex] = 0.147 mole of AgCl produced.

Now we need to find the amount of NF3 that can be formed by the complete reactions of each of the reactants. If all of the N2 was used up in the reaction, how many moles of NF3 would be produced

Answers

The question is incomplete, the complete question is:

Nitrogen and fluorine react to form nitrogen fluoride according to the chemical equation:

[tex]N_2(g)+3F_2(g)\rightarrow 2NF_3(g)[/tex]

A sample contains 19.3 g of [tex]N_2[/tex] is reacted with 19.3 g of [tex]F_2[/tex]. Now we need to find the amount of [tex]NF_3[/tex] that can be formed by the complete reactions of each of the reactants.

If all of the [tex]N_2[/tex] was used up in the reaction, how many moles of [tex]NF_3[/tex] would be produced?

Answer: 1.378 moles of [tex]NF_3[/tex] are produced in the reaction.

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]       ......(1)

Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.

Excess reagent is defined as the reagent which is left behind after the completion of the reaction.

In the given chemical reaction, [tex]N_2[/tex] is considered as a limiting reagent because it limits the formation of the product and it was completely consumed in the reaction.

We are given:

Mass of [tex]N_2[/tex] = 19.3 g

Molar mass of [tex]N_2[/tex] = 28.02 g/mol

Putting values in equation 1:

[tex]\text{Moles of }N_2=\frac{19.3g}{28.02g/mol}=0.689mol[/tex]

For the given chemical reaction:

[tex]N_2(g)+3F_2(g)\rightarrow 2NF_3(g)[/tex]

By the stoichiometry of the reaction:

1 mole of [tex]N_2[/tex] produces 2 moles of [tex]NF_3[/tex]

So, 0.689 moles of [tex]N_2[/tex] will produce = [tex]\frac{2}{1}\times 0.689=1.378mol[/tex] of [tex]NF_3[/tex]

Hence, 1.378 moles of [tex]NF_3[/tex] are produced in the reaction.

What will be produced at the cathode during the electrolysis of an aqueous solution of magnesium iodide, MgI2

Answers

Answer:

At the cathode during the electrolysis of an aqueous solution of magnesium iodide, MgI2 , 2I−(aq) is produced

Explanation:

At cathode, reduction reaction takes place.

The dissociation of MgI2 in aqueous solution is Mg2+(aq) and 2I−(aq)

Here, the Iodine reduces to 2I−(aq) from state of 0 (MgI2) to state of -1 (2I−(aq))

Hence, at the cathode during the electrolysis of an aqueous solution of magnesium iodide, MgI2 , 2I−(aq) is produced

Answer:

During electrolysis of an aqueous solution of magnesium iodide, MgI2 , 2I−(aq) is produced at the cathode

Explanation:

Electrolysis is a process whereby ionic compound is broken down or degraded into smaller substances when electric current flow through it.

During electrolysis of magnesium iodide, At the cathode reduction reaction occur .

MgI2 is dissociated to is Mg2+(aq) and 2I−(aq)

Then Iodine is reduced to 2I−(aq) which is 0 in (MgI2) then change to -1 (2I−(aq))

Therefore;

During electrolysis of an aqueous solution of magnesium iodide, MgI2 , 2I−(aq) is produced at the cathode.

please help me quickly ????

Calculate the equilibrium solubility of silver arsenate

(Ksp = 6 * 10-23) in a solution that buffered to a pH of :

a) 3

b) 6

c) 9

For H3ASO4

Ka1 = 5 * 10-3

Ka2 = 1.1 * 10-7

Ka3 = 3.2 * 10-12​

Answers

Answer:

sorry don't know the answer!!!

Magnesium metal reacts with a solution of silver nitrate in a single-replacement reaction, producing aqueous magnesium
nitrate and silver metal.
If a reaction starts with 0.480 mol Mg, how many moles of silver are produced?
You must show a proper set up for the calculation, the answer with a proper unit, and
the proper significant figures.

Answers

Answer:

0.960 mol of Ag

Explanation:

Mg(s) + 2AgNO3(aq) → Mg(NO3)2(aq) + 2Ag(s)

1.00 mol of Mg ---- 2.00 mol of Ag

0.480 mol of Mg ---- x

x = (0.480×2)/1 = 0.960 mol of Ag

Write the formulas for each of the compounds in the following table.
1.
Ferric sulfate
2.
Strontium oxalate
3
.
Chromic acid
4.
Nickel(III) carbonate
5.
Silver bromate
6
.
Dinitrogen difluoride
1.
Magnesium molybdate
8.
Sodium hydrogen phosphate​

Answers

Answer:

1. Ferric sulfate - Fe2(SO4)3

2. Strontium oxalate – SrC2O4

3. Chromic acid – CrO3

4. Nickel (III) carbonate – NiCO3

5. Silver bromate – AgBrO3

6. Dinitrogen difluoride - N2H2

7. Magnesium molybdate – MgMoO4

8. Sodium hydrogen phosphate - Na2PO4

Which piece of glassware shown below is used to hold and dispense a solution of known concentration during a titration?

Answers

Answer:

Answer C

Explanation:

Got it off of q**zlet ;)

Answer

Its C confirmed

Explanation:

Just did the test

The MO diagram of CN is similar to N2. Based on the molecular orbital energy-level diagram of CN, which of the following statements are correct?

i. The CN bond order is 2.
ii. CN is diamagnetic.
iii. The bond enthalpy in CN- ion is higher than CN.
iv. CN has longer bond length than CN-

answer choices:
a. ii, iv
b. iii, iv
c. i, iii
d. i, ii
e. i, iv

Answers

Answer:

Nitrogen molecule (N2)

The electronic configuration of nitrogen (Z=7) = 1s2 2s2 2px12py12pz1.

The total number of electrons present in the nitrogen molecule (N2) is 14.

In order to maximize energy, these 14 electrons can be accommodated in the different molecular orbitals.

N2: KK'(σ2s)2 (σ*2s)2 (π2Px)2 (π2py)2 (σ2pz)2

Here (σ1s)2 (σ*1s)2 part of the configuration is abbreviated as KK’, which denotes the K shells of the two atoms. In calculating bond order, we can ignore KK’, as it includes two bonding and two antibonding electrons.

The bond order of N2can be calculated as follows:

Here, Nb = 10 and Na = 4

Bond order = (Nb−Na) /2

B.O = (10−4)/2

B.O = 3

So your answer should be C3.

How do isotopes of the same atom react chemically? How do isotopes of the same atom compare in size?

Answers

Atoms of the same elements differing in the number of neutrons in their nuclei are known as isotopes. Thus, isotopes of an element have the same atomic number but different atomic mass number. Isotopes of an element have similar chemical properties but different physical properties.

What would the IUPAC name be?

Answers

Answer:

methyl ethanoate

Explanation:

To name the compound given above, the following must be obtained:

1. Determine the functional group of the compound.

In this case, the functional group is R–COOR' where R and R' are alkyl groups. Thus, the compound is an ester.

2. Determine the longest chain before the functional group and the compound after the functional group.

In this case, the longest chain before the functional group is carbon 2 i.e ethane and the compound after the functional group is methyl.

3. Name the compound by naming the compound after the functional group first, followed by the compound before the functional group and ending it with –oate.

This is illustrated below:

After the functional group => methyl

Before the functional group => ethane

Name of the compound => methyl ethanoate

When an acid reacts with a strong base which product always forms

Answers

Answer:طيزي

Explanation:

When you test starch with Barfoed’s reagent, what would be the answer, positive or negative?

Answers

Answer:

It would test positive.

if you were conducting an experiment with pepsin which has an optimal enzymatic actigity at ph 2.3, wat buffer would be the best choice

Answers

Answer: One with a pKa of 1.9

Hope this helps <3

P.S Fun Fact~~

There are only two words in the English language that have all five vowels in order: "abstemious" and "facetious."!

Answer:

Explanation:   Is there choises? H3PO4 / NaH2PO4 buffer with equal concentrations would form a buffer solution pH = 2.15

I dont understand this

Answers

Answer:

me too

Explanation:

The last one Metallic bonding

hello HELP ME pLS ANYONE with this question I will give u 18 points pls I need real help here:((​

Answers

Answer:

Boiling - The process of a liquid changing to gas.

Boiling point - The temperature at which a liquid boils.

Condensing - The process of a gas changing to a liquid.

Distillate - The liquid collect from the condenser.

Residue - The liquid left behind in the distillation flask.

Vapour - Another name for gas.

Hope it helps :)

Can someone help me with a bio organic questions??‍♀️

Answers

Yeah what is the question
I believe the answer could be “alkanes”

Look at the table of dissociation constants for some acids.

Acid Ka Acetic acid 18 x 10-6 1.2 x 10-2 Chlorous acid Nitrous acid 4.0 x 10 -4 Propionic acid 1.3 x 10-5

Which of these is the strongest acid?

acetic acid
chlorous acid
nitrous acid
propionic acid

*Answer is B*​

Answers

Answer:

chlorous acid

Explanation:

The acidic equilibrium of weak acids, HX, occurs as follows:

HX ⇄ H+ + X-

Where Ka is written as:

Ka = [H+] [X-] / [HX]

The strongest acid is the acid that produce more H+. The acid with the higher Ka is the acid that produce more [H+] and is, thus, the strongest acid.

The higher Ka is the Ka of chlorus acid = 1.2x10-2

Right answer is:

chlorous acid

Answer:

chlorous acid :)

Explanation:

Consider the reaction 4FeS2 + 11O2 → 2Fe2O3 + 8SO2. If 8 moles of FeS2 react with 15 moles of O2, what is the limiting reactant? (3 points)


SO2

O2

Fe2O3

FeS2

Answers

Answer:

O2

Explanation:

for find the limiting reactant you must calculate the moles of the reactants from the amount that you have and from the MM:

MM FeS2 = 120n  = 26.2g / 120g/mol = 0,218 mol

MM O2  = 32n = 5,44g/32g/mol = 0,17 mol

The limiting reactant is  

O2

7. In science, the process/thing that you examine/focus on is called the ??
and anything outside of this focus is called the ??

Answers

Answer:

Subject of the experiment and out of scope

Explanation:

In any research study, the process of thing studied is basically the subject of the experiment on which research is conducted to determine the outcomes. If any thing lies out of the experimental process reach, then it is said to be out of scope of the experiment.

BRAINIEST AND POINTS
Which option below accurately describes the relationship between frequency and wavelength?
A. The higher the frequency the shorter the wavelength.
B. The lower the frequency the shorter the wavelength.

Answers

Answer:

Hi, there your answer is A. As the frequency of a wave increases, the shorter its wavelength is.

Explanation:

When frequency increases, wavelength decreases.

Hope this Helps :)

A potted plant is placed under a grow lamp, which provides 6,400 J of energy to the plant and the soil over the course of an hour. The specific heat capacity of the soil is about 0.840 J/g°C and the temperature goes up by 9.25°C of soil. How many grams of soil are there?

Answers

Answer:

823.7g

Explanation:

Using the formula as follows:

Q = m × c × ∆T

Where;

Q = amount of heat (J)

m = mass of substance (g)

c = specific heat capacity (J/g°C)

∆T = change in temperature (°C)

Using the information given in this question as follows:

Q = 6,400 J

m = ?

c of soil = 0.840 J/g°C

∆T = 9.25°C

Using Q = mc∆T

m = Q ÷ c∆T

m = 6,400 ÷ (0.840 × 9.25)

m = 6400 ÷ 7.77

m = 823.7g

Answer:

There are 823.68 grams.

Explanation:

Calorimetry is responsible for measuring the amount of heat generated or lost in certain physical or chemical processes.

Between heat and temperature there is a relationship of direct proportionality. The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat by the mass of the body. In summary, the amount of heat Q that receives or transmits a mass m of a substance with specific heat C to raise its temperature from T1 to T2 is given by the formula:

Q= C*m* (T2- T1) = C*m* ΔT

In this case:

Q= 6400 JC= 0.840 [tex]\frac{J}{g*C}[/tex]m= ?ΔT= 9.25 C

Replacing:

6400J= 0.840 [tex]\frac{J}{g*C}[/tex] *m* 9.25 C

Solving:

[tex]m=\frac{6400 J}{0.840 \frac{J}{g*C} *9.25 C}[/tex]

m=823.68 grams

There are 823.68 grams.

THIS NOT MY WORK. its for my sister. HELP HER

Answers

Answer:

Your answer will be b(molten material from the outer core makes its way to the surface of earth)

Explanation:

Answer:

C

Explanation:

I'm pretty sure molten material comes from the inner core. I think you can search up this though, try to find where molten material comes from. Goodluck!

Which of these is NOT a producer in the coral reef ecosystem? *
1. phytoplankton
2. sea grass
3. microalgae
4. coral

Answers

Answer:

option number 4. 'coral'

Explanation:

-

Calculate the volume of 0.07216 M AgNO3 needed to react exactly with 0.3572 g of pure Na2CO3 to produce solid Ag2CO3.

Answers

Answer:

93.4 mL

Explanation:

Let's state the reaction:

2AgNO₃ +  Na₂CO₃  →   Ag₂CO₃  +  2NaNO₃

We determine the moles of sodium carbonate:

0.3572 g . 1mol / 105.98g = 3.37×10⁻³ moles

Ratio is 1:2. We say:

1 mol of sodium carbonate react to 2 moles of silver nitrate

Then, our 3.37×10⁻³ moles of carbonate may react to: 3.37×10⁻³ . 2

= 6.74×10⁻³ moles

If we convert to mmoles → 6.74×10⁻³ mol . 1000 mmol / mol = 6.74 mmol

Molarity is mol/L but we can use mmol /mL

6.74 mol / volume in mL = 0.07216 M

6.74 mol / 0.07216 M = volume in mL → 93.4 mL

Given the reaction: N2 + O2 = 2NO for which the Keq at 2273 K is 1.2 x 10-4
a. Write the equilibrium constant expression for the reaction.
b. Write the equation that would allow you solve for the concentration of NO.
c. What is the concentration of NO if [NZ] = 0.166M and [02] = 0.145M?

Answers

Answer:

(a): The expression of equilibrium constant is [tex]K_{eq}=\frac{[NO]^2}{[N_2][O_2]}[/tex]

(b): The equation to solve the concentration of NO is [tex][NO]=\sqrt{K_{eq}\times [N_2]\times [O_2]}[/tex]

(c): The concentration of NO is 0.0017 M.

Explanation:

The equilibrium constant is defined as the ratio of the concentration of products to the concentration of reactants raised to the power of the stoichiometric coefficient of each. It is represented by the term [tex]K_{eq}[/tex]

(a):

The given chemical equation follows:

[tex]N_2+O_2\rightarrow 2NO[/tex]

The expression for equilbrium constant will be:

[tex]K_{eq}=\frac{[NO]^2}{[N_2][O_2]}[/tex]

(b):

The equation to solve the concentration of NO follows:

[tex][NO]=\sqrt{K_{eq}\times [N_2]\times [O_2]}[/tex]            ......(1)

(c):

Given values:

[tex]K_{eq}=1.2\times 10^{-4}[/tex]

[tex][N_2]_{eq}=0.166M[/tex]

[tex][O_2]_{eq}=0.145M[/tex]

Plugging values in equation 1, we get:

[tex][NO]=\sqrt{(1.2\times 10^{-4})\times 0.166\times 0.145}[/tex]

[tex][NO]=\sqrt{2.88\times 10^{-6}}[/tex]

[tex][NO]=0.0017 M[/tex]

Hence, the concentration of NO is 0.0017 M.

How many moles of O2 did you produce the 8.31 moles of H2O

Answers

the equation is not present.

What is the total mass of products formed when 64.18 grams of CH4 is burned with excess oxygen?

Answers

80 grams of product is formed when 16 grams of CH₄ is burnt in excess of Oxygen so ur answer is

80 GRAMS

Hydration of alkynes gives good yields of single compounds only with symmetrical or terminal alkynes. Draw the major organic product(s) formed when 3-methylcyclodecyne undergoes hydration in the presence of HgSO4 and H2SO4.

Answers

Answer:

Following are the solution to the given choice:

Explanation:

Hex-2-yne is just not alkyne symmetric, therefore two things respectively hexan-3-one and hexan-2-one are to be given.

The attached file it displayed the response along with the mechanism, please find the.

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