Answer:
The answer is C
Explanation:
Thomson conducted many tests with cathode rays. Which led to his discovery of the electron.
The pH scale measures ___.
A. The concentration of hydrogen ions
B. The strength of solutions from 1 to 12
C. The concentration of bases
D. The concentration of acids
Answer:
a
Explanation:
it is the concentration of the hydrogen ion, more hydrogen ion more acidic less hydrogen ion less acidic and alkaline.
According to Valence Shell Electron Pair Repulsion (VSEPR) theory, which statement is correct? If a molecule has four pairs of electrons, it will always have a tetrahedral structure. If a molecule is made up of three atoms, it will always have a linear structure. If a molecule is bent, it will always have unpaired electrons around the central atom. If a molecule has three atoms around a central atom, it will always be trigonal planar.
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:
To reduce the electron repellence atom having four pairs of electrons will always accommodate to a tetrahedral structure.An atom comprising four pairs of electrons will have no lone pairs and hence, tetrahedral geometry.An example of tetrahedral geometry is methane (CH4).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
find the mass of electron
Answer: mass of electron is
9.10938356 × 10^-31 kilograms
Explanation:
Describe two ways the material in illustrates the importance of creativity in scientific investigations
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.
what information does a chemical equation contain
Answer:
Chemicals should involve information about properties and reactants.
A sample of 2.00 moles of oxygen at 45°C and 98.6 kPa occupies what volume?
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
About Salva Chapter 14
1.Why isn’t Nya happy when the borehole water starts flowing?
2.How much time has now passed since Salva fled from his school?
3.What was life like in the Kakuma and Ifo refugee camps?How did they compare?
4.What does Salva mean when he thinks,”It was hard to keep hope alive when there was so little to feed it?”
5.Where does Salva finally find this hope?
Answer:
Because it is muddy and dirty.9 yearsDreadful / Compared The Ifo and Kakuma camps: Isolated areasThere was no way Salva could ever reach his goal of branching out into the world if he was stuck at the camp.When he hears that 3000 boys will be chosen to go to America.Why does oxygen have stronger attractive forces between its nucleus and valence electrons than nitrogen?
Fill in the coefficients that will balance the following reaction: (Note: Use 1 as coefficient where appropriate.) C3H7OH+O2-- CO2 +H2O
The balanced equation :
2C₃H₇OH+9O₂⇒ 6CO₂ +8H₂O
Further explanationGiven
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
What is the correct order of the scientists in order of their work related to the structure of an atom from earliest to most recent?
Neils Bohr, Ernest Rutherford, JJ Thomson, John Dalton, Democritus and Erwin Schrodinger
Erwin Schrodinger, JJ Thomson, John Dalton, Neils Bohr, Ernest Rutherford and Democritus
Democritus, John Dalton, JJ Thomson, Ernest Rutherford, Neils Bohr and Erwin Schrodinger
John Dalton, Neils Bohr, JJ Thomson, Democritus, and Ernest Rutherford and Erwin Schrodinger
PLEASE HELP !!!
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
which metal can be obtain from calvertie ores?
Answer:
Ore
hope this helps
thanks for the points
the term pH was discovered by which scientist
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
1. In a Stock system name such as iron(III) sulfate, the Roman numeral tells us (a) how many atoms of Fe are in one formula unit. (b) how many sulfate ions can be attached to the iron atom. (c) the charge on each Fe ion. (d) the total positive charge of the formula unit. 2. Changing a subscript in a correctly written chemical formula (a) changes the number of moles represented by the formula. (b) changes the charges on the other ions in the compound. (c) changes the formula so that it no longer represents the compound it previously represented. (d) has no effect on the formula.
Answer:
See explanation
Explanation:
1) The formula of the compound is Fe2(SO4)3. There are two ion atoms in any formula unit as we can see here. Three sulphate ions are attached to iron. Each iron ion carries a +3 charge as we saw in the formula. The total positive charge in each formula unit is +6.
Changing a subscript in a correctly written chemical formula changes the formula so that it no longer represents the compound it previously represented. Hence FeSO4 is a different compound from Fe2(SO4)3.
help me pleaseeee, if you do tyy :)
in one molecule we have one oxygen atom so we will have 4 oxygen atoms in 4 molecules
a)Calculate the mass of NaNO3 that heated strongly and produced 4.5 dm3(cubic decimeter) of O2 gas.
The chemical equation for a chemical reaction is given below (2)
2NaNO3 ---> 2NaNO2 +O2
b) Calculate the concentration of HCl solution formed by dissolving 200 g HCl in 300 CM3 of water.(2)
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
Help ASAP ......begdhzhshs
Answer:
thunderstorms
Explanation:
Models are used to show which qualities of a compound’s chemical structure? a. bond angles c. bond length b. element color d. both a and c
Answer:
a. bond angles c. bond length
Explanation:
Models are abstractions of the real world. They are used to present either real or hypothetical situations either visually, graphically or through mathematical expressions.
In chemistry, to show bond angles and bond lengths, different models are used. One of such is the VESPR - valence shell electron pair repulsion- theory which the model upon which the bond relationships between elements in a compound is shown. Also, the hybridization schemes are excellent models for showing bond relationships.What is the molecular formula of a substance whose molar mass is 166.8 grams and its empirical formula is C2H4N2?
Answer:
C4H2O6
Explanation:
In order to become stable, Potassium, K, will _______ and have a resulting charge of _____.
A)gain an electron, +1
B)gain 7 electrons, +7
C)lose an electron , +1
D)gain 7 electrons, -7
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
Minerals from water pass through the mold and over time the minerals fill that mold and it then becomes a cast in the same shape of the body of the animal that died?
True
False
Write out the chemical equations showing how a buffer solution made from H2PO4- and HPO42- would react to the addition of an acid (H+ ions) or a base (OH- ions).
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⁻.
A student was tasked with experimentally determining the mole ratio of strontium chlorate hexahydrate. The students data follows below. Determine the experimental molar ratio for strontium chlorate hexahydrate to proper significant figures (4) based on the data below. Calculate the students percent error.
Mass of clean dry crucible – 21.05 g
mass of crucible and sample – 23.36 g
mass of crucible & sample after heating – 22.49 g
Would this be point D or point E? (Picture)
List six elements with only 1 electron in an s orbital
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.
Consider the reaction H2O(g)+Cl2O(g)=2HClO(g). At equilibrium,the concentrations of the different species:[H2O]=0.077M,[Cl2O]=0.077M,[HClO]=0.023M. What is the equilibrium constant for the reaction at this temperature?
Choices: 0.089, 0.26, 3.9, or 11
The equilibrium constant K : 0.089
Further explanationGiven
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]
A. 207 kJ
B. 4730 kJ
O C. 9460 kJ
O D. 414 kJ
Answer:
C = 9460 Kj
Explanation:
Given data:
Mass of copper = 2kg
Latent heat of vaporization = 4730 Kj/Kg
Energy required to vaporize 2kg copper = ?
Solution:
Equation
Q= mLvap
by putting values,
Q= 2kg × 4730 Kj/Kg
Q = 9460 Kj
Can someone please help me and explain how to do this :')
How many moles of O₂ are needed to produce 3.17 mol of carbon monoxide from it's elements by a synthesis reaction?
Answer:
this is the answer explanation of previous question. as what you say in comment i do that
When magnesium is heated in air, the product formed is heavier than the original ribbon. On the other hand when potassium magnate (7) is heated in air, the product formed is light. Explain the different observation
Answer:
See the answer below
Explanation:
When magnesium is heated in air, the element combines with oxygen to form a compound known as magnesium oxide according to the following equation:
[tex]2Mg(s) + O_2 (g)--> 2MgO (s)[/tex]
Hence, the product formed - a combination of magnesium and the oxygen component of air - is heavier than the original magnesium ribbon.
On the other hand, potassium manganate (7) is heated in air and decompose to form potassium manganate (6), manganate oxide, and oxygen gas according to the following equation:
[tex]2KMnO_4 --> K_2MnO_4 + MnO_2 + O_2[/tex]
Hence, the final product formed is lighter than the original product because oxygen gas has been evolved.
Answer:
During the heating of magnesium in air, it gains mass with the addition of oxygen present in air to form the oxide. However, during the heating of potassium manganate (vii), it decomposes or breaks down to simpler products and oxygen gas is given off.
Explanation:
During the heating of magnesium in air, it gains mass with the addition of oxygen present in air to form the oxide.
The equation for the reaction is given below:
2Mg(s) + O2(g) ---> 2Mg0
The molar mass of the magnesium metal is 24.0 g while the mass of the magnesium oxide is 40.0 g. The total mass of the metal before heating is 24 × 2. + 32 = 48.0 g. The total mass after heating = 48 + 32 = 80.0 g. Therefore, there is an increase in mass.
However, during the heating of potassium manganate (vii), it decomposes or breaks down to simpler products and oxygen gas is given off. The equation for the reaction is given below;
2KMnO4(s) ----> K2MnO4(s) + MnO2(s) + O2(g)
With the evolution of oxygen gas, there's a loss in mass of potassium manganate (vii). Molar mass of KMnO4 is 158.0 g while the mass of K2MnO4 is 197.0 g and that of MnO2 is 87.0 g. The total mass on the right hand side is 2 × 158 = 316.0 g. The total mass on the left-hand side with the exception of the gas evolved is 284.0 g. Therefore, there is a loss in mass.
How is Zinc chloride formed in the lab and please tell the steps
Answer:
When zinc metal is reacted with hydrochloric acid, hydrogen gas is released and an aqueous solution of zinc chloride is produced. ... It is important that all of the zinc used be reacted and that large excess amounts of hydrochloric acid not be used.
Anhydrous zinc chloride is synthesized by treating zinc with hydrogen chloride. Whereas, hydrated and aqueous forms of zinc chloride are prepared by treating zinc with hydrochloric acid. Zinc metal could either be in the form of zinc sulfide or zinc oxide
Have a nice Day , Hope this helped you I would appreciate it if you could mark my answer brainliest
Merry Christmas
Answer: Anhydrous zinc chloride is synthesized by treating zinc with hydrogen chloride. ... Zinc metal could either be in the form of zinc sulfide or zinc oxide. ZnS(s) + 2 HCl(aq) → ZnCl2(aq) + H2S(g) There are impurities present in zinc chloride samples due to hydrolysis.
got this from goo.gle
Hope this helps.......... Stay safe and have a Merry Christmas!!!!! :D
How many joules must be added to a 1000 g iron skillet to increase its temperature
from 25°C to 250°C? The specific heat of iron is 0.449 J/gºC.
A) 449 J
B) 101,025 J
C) 50,000 J
D) 112,250 J
Answer:
B) 101,025
Explanation:
1000g * 0.449 J/g Celsius * 225 Celsius = 101,025
I got 225C from 250C - 25C