what is this i need help please

Answer:

The central value of the sets of observation can be mean, median or mode depending upon the kind of data provided as all are measure of central tendency.

Explanation:

Answer:

C. democritusm John dalton, JJ Thomason, Ernest Rutherford, Neils Bohr, and Erwin Schrodinger.

The correct order of the scientists in order of their work related to the

structure of an atom from earliest to most recent include Democritus, John

Dalton, JJ Thomson, Ernest Rutherford, Neils Bohr, and Erwin Schrodinger.

Democritus was regarded as one of the earliest scientist who first proposed

atomic theory around 460 BC which was then modified and used by others

such as John Dalton, JJ Thomson, Ernest Rutherford and Neils Bohr.

The most recent of them all was Erwin Schrodinger which was  the wave

equation for electron movements in the 20th century.

Read more on https://brainly.com/question/20339664

Answer:

42686.04375

Explanation:

Multiply 847.3219 by 34.6 to get 29317.33774, then multiply this answer by 1.4560 to get the final answer which is 4286.04375.

The question is incomplete, the complete question is;

Anna is conducting an experiment to determine how weather affects cell phone reception. She is trying to decide the best way to conduct her experiment in order to collect meaningful data. Which of the following experiments would help Anna collect the best data? A. Test different cell phones in different locations on days with clear weather. B. Test different cell phones in different locations on days with rainy weather. C. Test a cell phone's reception in one location with clear weather and in another location with rainy weather. D. Test a cell phone's reception in the exact same location under various atmospheric conditions.

Answer:

D. Test a cell phone's reception in the exact same location under various atmospheric conditions.

Explanation:

In this experiment that Anna intends to carry out, the independent variable is the atmospheric condition. The dependent variable must be the cell phone reception, it is expected to change with  atmospheric conditions.

In order to obtain valid results, other factors such as  such as type of cellphone and location (control variables) must be held constant so as to collect the best data.

Answer:

What happens is...

Explanation:

Specifically, it allows your neurons, or nerve cells, to reorganize. When you sleep, your brain's glymphatic (waste clearance) system clears out waste from the central nervous system. It removes toxic byproducts from your brain, which build up throughout the day. This allows your brain to work well when you wake up.

Answer:

Chemicals should involve information about properties and reactants.

Answer:

Explanation:

Answer:

V = 53.83 L

Explanation:

Given data:

Number of moles = 2.00 mol

Temperature = 45°C (45+273 = 318 K)

Pressure = 98.6 KPa (98.6/101 = 0.97 atm)

Volume of gas = ?

Solution:

PV = nRT

R = general gas constant = 0.0821 atm.L/mol.K

0.97 atm × V = 2.00 mol × 0.0821 atm.L/mol. K × 318 K

V = 52.22 atm.L/0.97 atm

V = 53.83 L

The equilibrium constant K : 0.089

Given

Reaction

H₂O(g)+Cl₂O(g)⇔2HClO(g)

[H2O]=0.077M,[Cl2O]=0.077M,[HClO]=0.023M

Required

the equilibrium constant

Solution

The equilibrium constant or Kc is the value of the concentration product in the equilibrium state of the substance in the right segment divided by the product of the substance in the left section, each of which has a reaction coefficient raised  

[tex]\tt K=\dfrac{[HClO]^2}{[H_2O][Cl_2O]}\\\\K=\dfrac{0.023^2}{0.077\times 0.077}\\\\K=0.08922[/tex]

Answer:

[tex]Lithium=Li2s^1\\Sodium=Na3s^1\\Potassium=K4s^1\\Rubidium=Rb5s^1\\Cesium=Cs6s^1\\Francium=Fr7s^1[/tex]

Explanation:

When it comes to electron configuration and orbitals, it's important to first identify what exactly we are trying to identify. Below is a given example:

[tex]He1s^2[/tex]

[tex]He=element[/tex]

[tex]1=level[/tex]

[tex]s=orbital[/tex]

[tex](exponent)^2=electrons[/tex]

Looking at the periodic table, identify the alkali metal family on the periodic table, or group one elements:

[tex]Lithium=Li2s^1\\Sodium=Na3s^1\\Potassium=K4s^1\\Rubidium=Rb5s^1\\Cesium=Cs6s^1\\Francium=Fr7s^1[/tex]

Notice how each configuration has an exponent of [tex]1[/tex], representative of a single electron in their s-orbital.

Answer:

Ore

hope this helps

thanks for the points

Answer:

J.J Thompson make use of creativity to explain cathode ray tube experiment.

Also, creativity was used by Daltons to explain Joseph Proust's work.

Explanation:

This problem is all about the the beginning part of chemistry that is the atomic  theory. The atomic theory was starts from the time of people like Democritus and down to people like J.J Thompson and John Dalton. Although it has been registered and credited that Dalton is the father of atomic theory many people has also worked on it before him for instance person like Joseph Proust. The reason behind this because some works that has been done by other people such as Democritus[who was the first person to start atomic studies] does not have any scientific evidence.

Creativity is needed when it concerns scientific research and investigation. This is what scientists such as John Daltons and J.J Thompson have used. J.J Thompson make use of creativity to explain cathode ray tube experiment. Also, creativity was used by Daltons to explain Joseph Proust's work.

Answer: Option 1

Explanation: hopes it helps

Valence Shell Electron Pair Repulsion (VSEPR) theory is employed in prophesying the geometrical organisation of the specific molecule with the aid of electron sets found encompassing the atom.

The correct answer is:

Option A. If a molecule has four pairs of electrons, it will always have a tetrahedral structure.

This can be explained as:

Therefore atom containing four pairs of electrons will have a tetrahedral shape.

To learn more about VSEPR theory follow the link:

https://brainly.com/question/12775505

Answer:

a) 34 g

b) 18.33 moldm^-3

Explanation:

a) The equation of the reaction is;

2NaNO3----------> 2NaNO2 + O2

Let us recall that 1 mole of a gas occupies 22.4 dm^3. Since 1 mole of O2 is produced in the reaction, we can write;

2 moles of NaNO3 yields 22.4 dm^3 of O2

x moles of O2 yields 4.5 dm^3 of O2

x = 2 * 4.5/22.4

x = 0.4 moles of NaNO3

But number of moles = mass/molar mass

molar mass of NaNO3 = 85 g/mol

Mass of NaNO3 = 0.4 moles * 85 g/mol

Mass of NaNO3 = 34 g

b)

Number of moles in 200g of HCl = mass/molar mass

molar mass of HCl = 36.5 g/mol

Number of moles = 200g/36.5 = 5.5 moles

From;

Number of moles = concentration * volume in dm^3

concentration = Number of moles/ volume in dm^3

But volume = 300 cm^3 or 0.3 dm^3

concentration = 5.5/0.3 = 18.33 moldm^-3

Answer:

Such was the case with the concept of pH, introduced in 1909 by Søren Sørensen as a convenient way of expressing acidity—the negative logarithm of hydrogen ion concentration.Jan 8, 2018

Profession: Chemist

Answer:

this is the answer explanation of previous question. as what you say in comment i do that

Answer:

Explanation:

The pH of a solution can be found by using the formula

[tex]pH = - log [ {H}^{+} ][/tex]

From the question we have

[tex]pH = - log(1.2 \times {10}^{ - 2} ) \\ = 1.920818...[/tex]

We have the final answer as

Hope this helps you

Answer:

1.9

Explanation:

Answer:

kindly check the explanation section.

Explanation:

The two ions given in the question above that is Dihydrogenphosphate, H2PO4- and HPO42- are so important when it concerns buffering. During intracellular pH balancing the ions that is H2PO4- and HPO42- reacts with OH⁻ and H⁺ respectively. The equation for the chemical reaction is given below for both ions.

H₂PO₄⁻ + OH⁻  < =====================================> HPO₄²⁻ + H₂O.

HPO₄²⁻ + H⁺ <===========================================> H₂PO₄⁻.

Answer:

9.033 × 10²³ molecules

Explanation:

Given data:

Mass of oxygen = 48.0 g

Number of molecules = ?

Solution:

Number of moles of oxygen:

Number of moles = mass/molar mass

Number of moles = 48.0 g/ 32 g/mol

Number of moles = 1.5 mol

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ molecules

1.5 mol  × 6.022 × 10²³ molecules  / 1mol

9.033 × 10²³ molecules

Answer:

Mass of NaBr produced  = 23.67 g

Explanation:

Given data:

Mass of AgBr = 42.7 g

Mass of NaBr produced = ?

Solution:

Chemical equation:

2Na₂S₂O₃ + AgBr    →    NaBr + Na₃(Ag(S₂O₃)₂

Number of moles of AgBr:

Number of moles = mass/molar mass

Number of moles = 42.7 g/ 187.7 g/mol

Number of moles = 0.23 mol

now we will compare the moles of AgBr with NaBr.

             AgBr        :         NaBr

                1            :           1

              0.23       :         0.23

Mass of NaBr:

Mass = number of moles × molar mass

Mass = 0.23 mol × 102.89 g/mol

Mass = 23.67 g

Answer: Your mass would be the same, but you would weigh less because the gravity on the moon is less than it is on Earth.

Explanation:

Answer:

D

Explanation:

it doesn't matter how many protons k has all the answers have electron with the positive charge when is negative the question is trying to distract you D is the only one that would use the electrons sign correctly

The balanced equation :

2C₃H₇OH+9O₂⇒ 6CO₂ +8H₂O​​

Given

The following reaction(combustion of Propanol) :

C₃H₇OH+O₂⇒ CO₂ +H₂O​

Required

Balanced equation

Solution

Equalization of chemical reactions can be done using variables. Steps in equalizing the reaction equation:  

• 1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c, etc.  

• 2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index (subscript) between reactant and product  

• 3. Select the coefficient of the substance with the most complex chemical formula equal to 1  

1. Give coefficient

C₃H₇OH+aO₂⇒ bCO₂ +cH₂O​

2. Make an equation

C, left=3, right=b⇒b=3

H, left=8, right=2c⇒2c=8⇒c=4

O, left=1+2a, right=2b+c⇒1+2a=2b+c⇒1+2a=2.3+4⇒1+2a=10⇒2a=9⇒a=9/2

The equation becomes

C₃H₇OH+9/2O₂⇒ 3CO₂ +4H₂O x 2

2C₃H₇OH+9O₂⇒ 6CO₂ +8H₂O​​

Answer:

I'm pretty sure it's 15 electrons. Hope this helps :).

Explanation:

Answer:

A. HCl

Explanation:

on the left hand side we have reactants.

hope it helps!