Answer:
a) 4p ⇒ 4s transition is Allowed
b) 3d ⇒ 4s transition not allowed
Explanation:
a) 4p ⇒ 4s transition
This transition is allowed because for a 4p state; l = 1 and for a 4s state I = 0
hence Δl = 1 - 0 = 1
Energy of 4p ( Ei ) = 3.75eV
Energy of 4s ( E2 ) = 3.19 eV
where : λ = 1240 eV nm / ( E₂ - E₁ )
= 2214 nm ≈ 2.214 μm
b) 3d ⇒ 4s transition
This transition is not allowed
a 3d state , l = 2 while for 4s state l = 0
hence Δl = 2 - 0 = 2
therefore the transition is not allowed
KOH(Ac) + HNO3 → KNO3(Ac) + H2O
cual es su reacio
Answer:
corbonization for dictionnal
Explanation:
correct
Answer:
neutralization reaction forms water and salt , neutralization is the reaction!
Explanation:
How many ml of a 2.903 M NaOH solution are needed to produce 500.0 ml of a 0.3344M solution?
Answer:
57.6ml
Explanation:
Using dilution formula
C1V1 = C2V2
C1 = 2.903 M, V1 = ? , C2 = 0.3344 M , V2 = 500ml
2.903 × V1 = 0.3344 × 500
V1 =( 0.3344 × 500)/ 2.903
= 57.5956
≈ 57.6ml
Industrial chemists have to understand the chemistry of oxides.
For example, silicon dioxide is used in glass making and carbon monoxide is used in the
extraction of iron from iron ore.
(i) Explain how burning carbon in air can lead to the formation of carbon monoxide.
(2)
(ii) Write the balanced equation for the reaction between silicon and oxygen.
(2)
Answer:
carbon monoxide can be formed due to incomplete combustion of carbon due to insufficient oxygen supply
2C+O2___2CO
Si+O2____SiO2
How many atoms are AI(OH)3 ?
Answer:
It has a total of three elements and seven atoms. Another use that aluminum hydroxide has is it treats the symptoms of too much stomach acid. Some examples of what it treats are: upset stomach, heartburn, and acid indigestion.
Explanation:
Atomicity is the no of atoms present in one molecule. Atomicity of Al(OH)3 = 7.
what is the true of lewis base
Answer: To answer your question of what is true of a lewis base, it is true that a lewis base donates electron pairs.
Explanation: A Lewis base is any substance, such as the OH- ion, that can donate a pair of nonbonding electrons. A Lewis base is therefore an electron-pair donor.
Polyvalent ions are
1) Anions with variable charges
2) Cations from columns 3 to 12
3) Ions that can be positive or negative
calculate the molar mass for each of the following compounds 7. PbSO
8. Ca(OH)2
9. Na3PO4
10. (NH4)2CO3
11. C6H12O6
12. Fe3(PO4)2
13. (NH4)2S
14. Zn(C2H3O2)2
Answer:
Fe3(PO4)2
Explanation:
calculate the molar mass for each of the following compounds 7. PbSO
8. Ca(OH)2
9. Na3PO4
10. (NH4)2CO3
11. C6H12O6
12. Fe3(PO4)2
13. (NH4)2S
14. Zn(C2H3O2)2
"Aqueous barium chloride reacts with aqueous sodium sulfate
to produce solid barium sulfate and aqueous sodium chloride."
Which chemical equation correctly translates the description
above?
Answer:
u should go to gathmath
Explanation:
it's alot better
What is the molecular geometry if you have a double bond, a single bond and 1 lone pair around the central atom?
Answer:
4 pairs are needed for the bonds, leaving 1 lone pair. Each double bond uses 2 bond pairs and can be thought of as a single unit. There are 2 double bond units and 1 lone pair, which will try to get as far apart as possible - taking up a trigonal planar arrangement.
is a physiologist. Which would most likely be the main focus of her studies?
how atoms bond to form different kinds of matter
how subatomic particles interact and make up atoms
how certain molecules affect the function of the human heart
how the structure of the human brain may differ between humans
A team of scientists is conducting tests to measure the boiling point of a liquid using a thermometer in the liquid. The team is
then recording the temperature where the liquid changes from a liquid to a gas rapidly. After 100 trials, the results are 5 degrees
below the expected results. Which next step is most reasonable? (1 point)
O checking the calibration of the thermometer to ensure that it is giving accurate readings
O assuming that the new results are incorrect
O assuming that the previous measurements are incorrect
O checking the insulation of the apparatus to find out if heat is escaping
The most reasonable step to take will be to check the calibration of the
thermometer to ensure that it is giving accurate readings.
Experiments which are done to be give the same results under standard
conditions. Common causes of incorrect results during the analysis of
boiling point of substances include heating the substance too rapidly or
the thermometer not being properly calibrated.
The thermometer is used to measure the temperature and so must be
properly calibrated to give accurate readings.
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What does lowercase v represent in this formula?
If 3.5 mols of P2O3 are formed, how many
moles of P4 reacted?
P2 is 3.5 for p4= 2p2 i.e 2*3.5=7
Answer;561gp203 are required to
produce 10.2 mol H3p03
How are oxidation-reduction reactions related to how you use energy?
Answer:
In oxidation reduction reactions, one species gets reduced by taking on electron(s) and another species gets oxidized by losing electrons. They also flow by a wire
Explanation:
Sulfuric acid reacts with sodium carbonate to form water, a salt, and a gas. Write the formulas for the salt and other compound that are formed in the reaction.
Answer:
H2So4 + Na2Co3 -> H20 + Na2So4 + CO2
The chemical formulas for the salt and other compound that are formed in the reaction are Na₂SO₄,H₂O and CO₂.
What is chemical formula?Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
There are four types of chemical formula:
1)empirical formula
2) structural formula
3)condensed formula
4)molecular formula
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13) Which of the following is NOT a true statement concerning what happens in all chemical
reactions
A) The ways in which atoms are joined together are changed
B) New atoms are formed as products,
C) The starting materials are named reactants.
D) The bonds of the reactants are broken and new bonds of the products are formed,
E) in a word equation representing a chemical reaction, the reactants are written on the left
and the products on the right
BARI
Which of these is a balanced chemical equation?
Revise the following statement to make it true:
All living things inside of an area are part of the population.
Answer:
All the individuals of a species living within a specific area are collectively called a population.
Explanation:
1) Which statement best describes the usefulness of a model to investigate molecules at the microscopic level?(1 point)
A model’s usefulness depends on whether direct observations of phenomena can be made.
All models are useful.
A model’s usefulness depends on the accuracy of its predictions.
Models are not useful at all.
2) Which scientist contributed to molecular theory by explaining that gas pressure is caused by the impact of gas molecules on surfaces?(1 point)
Daniel Bernoulli
Amedeo Avogadro
John Dalton
Robert Boyle
3) Which term did Avogadro create?(1 point)
molecule
microscope
kinetic energy
atom
4) Which statement best describes the development of theories that connected microscopic and macroscopic phenomena?(1 point)
It took several hundred years for scientists to develop current theories, and they are essentially concrete.
It only took a few decades for scientists to develop current theories, and they are still being revised to this day.
It only took a few decades for scientists to develop current theories, and they are essentially concrete.
It took several hundred years for scientists to develop current theories, and they are still being revised to this day.
5) How can the results of experiments investigating the relationship between microscopic and macroscopic phenomena affect a model of molecular theory?(1 point)
Consistent results support the validity of the model, while inconsistent results require throwing out the model entirely.
Consistent results require throwing out the model entirely, while inconsistent results support the validity of the model.
Consistent results support the validity of the model, while inconsistent results indicate the need to modify the model.
Consistent results indicate the need to modify the model, while inconsistent results support the validity of the model.
Answer:
1. A model’s usefulness depends on the accuracy of its predictions.
2. Daniel Bernoulli
3. molecule
4. It took several hundred years for scientists to develop current theories, and they are still being revised to this day.
5. Consistent results support the validity of the model, while inconsistent results indicate the need to modify the model.
Explanation:
The discovery that macroscopic and microscopic phenomena are connected took several hundred years.
A model is a representation of a real life system that serves as a tool for predictions and explanation. Since models serve a predictive purpose, a model’s usefulness depends on the accuracy of its predictions.
The pressure of a gas is caused by the collision of gas molecules with the walls of the container. This was established by the scientist called Daniel Bernoulli.
Avogadro was able to create the term molecule to describe a substance that has independent existence. The discovery that macroscopic and microscopic phenomena are connected took several hundred years. It took several hundred years for scientists to develop current theories, and they are still being revised to this day.
The results of experiments investigating the relationship between microscopic and macroscopic phenomena affect a model of molecular theory in the sense that consistent results support the validity of the model, while inconsistent results indicate the need to modify the model.
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The ___ variable responds to the __ variable and goes on the Y-axis.
1. Dependent, Independent
2. Independent, Dependent
3. Control, Constant
4. Constant, Control
Answer: 1. Dependent, Independent The dependent variable responds to the independent variable and goes on the Y-axis.
Explanation: The independent variable is controlled or manipulated by the experimenter. For example, someone's age might be an independent variable. Other factors (such as what they eat, how much they go to school, how much television they watch) aren't going to change a person's age.The dependent variable is what you are measuring. For example, a test score could be a dependent variable because it could change depending on several factors such as how much you studied, how much sleep you got the night before you took the test, or even how hungry you were when you took it.
How that helps. :)
The dependent variable responds to the independent variable and goes on the Y-axis. Therefore, option A is correct.
What is dependent variable ?In mathematical modeling, statistical modeling, and experimental sciences, there are dependent and independent variables. Dependent variables are so-called because, during an experiment, their values are examined on the assumption or presumption that they are governed by the values of other variables.
the dependent variable on other measurable variables As a result of an experimental manipulation of the independent variable or variables, these variables should change.
What you track in the experiment and what is impacted by it are both considered dependent variables. The independent variable affects the dependent variable's behavior. Because it "depends" on the independent variable, it is known as a dependent variable.
Thus, option A is correct.
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(QUICK)
What is the percent yield if the actual yield is 1.5g and the theoretical yield is 4.5g?
Answer:
33.3% (depending on how many significant figures you need)
Explanation:
Actual yield divided by theoretical yield times 100%
The gas in a 250. mL piston experiences a change in pressure from 1.00 atm to 2.25 atm. What is the new volume (in mL) assuming the moles of gas and temperature are held constant?
Answer:
111.11 mLExplanation:
Since the moles of gas and temperature are held constant the new volume can be found by using the formula for Boyle's law
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
From the question
P1 = 1 atm
P2 = 2.25 atm
V1 = 250 mL
We have
[tex]V_2 = \frac{250 \times 1}{2.25} = \frac{250}{2.25} \\ = 111.1111111...[/tex]
We have the final answer as
111.11 mLHope this helps you
what is the mass number of an atom that has six protons. six electrons, and eight neutrons?
Mass number is the sum of the total number of nucleons (neutrons + protons) present in the atom.
Mass number = Protons + Neutrons
Mass number = 6 + 8
Mass number = 14
_______
Hope it helps ⚜
How are oxidation-reduction reactions related to how you use energy?
Answer:
In oxidation reduction reactions, one species gets reduced by taking on electron(s) and another species gets oxidized by losing electrons. The movement of electrons can be used to do work. ... The electron flow can be run through a wire and these electrons can be used to do work (like run a battery). Hope this helps.
Select the correct answer. What does the kinetic theory state about the relationship between the speed and temperature of gas molecules? A. As the temperature increases, the speed of gas molecules remains constant. B. As the temperature increases, the speed of gas molecules decreases. C. As the temperature increases, the speed of gas molecules increases. D. As the speed of gas molecules increases, the temperature becomes constant. E. As the temperature decreases, the speed of gas molecules increases.
Answer:
C. As the temperature increases,the speed of gas molecules increase.
describe an experiment that would show that intramolecular forces (attractions between atoms within molecules) are stronger than intermolecular forces (attractions between molecules).
Answer:
Molecules don’t have to collide with each other in order to experience intermolecular forces.
Molecules with permanent dipoles, held in fixed orientation, such as water molecules in the solid state (ice), interact with a potential proportional to the inverse cube of distance. This intermolecular force always exists, no matter how far apart the molecules are; every water molecule interacts with every other water molecule. However, because it diminishes rapidly with distance, it tends to only be important at short distances. (In contrast, the potential between two ions goes as 1/r, and that between an ion and a dipole goes as 1/r^2.)
The van der Waals forces, of which London dispersion forces are the most important, are described by a potential proportional to the inverse sixth power of distance. Theoretically, those forces are always operating between any two atoms or molecules, but again, only become important at short distances.
Explanation:
hope this helps
What is the molarity of aqueous lithium bromide if 25.0 mL of LiBr reacts with 10.0 mL of 0.250 M Pb(NO 3) 2
The molarity of aqueous lithium bromide, LiBr solution is 0.2 M
We'll begin by calculating the number of mole of Pb(NO₃)₂ in the solution.
Volume = 10 mL = 10 / 1000 = 0.01 L Molarity of Pb(NO₃)₂ = 0.250 MMole of Pb(NO₃)₂ =?Mole = Molarity x Volume
Mole of Pb(NO₃)₂ = 0.25 × 0.01
Mole of Pb(NO₃)₂ = 0.0025 mole
Next, we shall determine the mole of LiBr required to react with 0.0025 mole of Pb(NO₃)₂
Pb(NO₃)₂ + 2LiBr —> PbBr₂ + 2LiNO₃
From the balanced equation above,
1 mole of Pb(NO₃)₂ reacted with 2 mole of LiBr.
Therefore,
0.0025 mole of Pb(NO₃)₂ will react with = 2 × 0.0025 = 0.005 mole of LiBr
Finally, we shall determine the molarity of the LiBr solution
Mole = 0.005 mole Volume = 25 mL = 25 / 1000 = 0.025 L Molarity of LiBr =?Molarity = mole / Volume
Molarity of LiBr = 0.005 / 0.025
Molarity of LiBr = 0.2 M
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NEED HELP ASAP WILL GIVE BRAINLIEST
Answer:
First we know that the molar mass of CO2 is 44.01g/mol, and that the sample of CO2 contains 3.408 x 10^21 molecules, and we have to find the mass of that sample.
We know that moles = mass/molar mass, if we rearrange the equation for mass, we'll get:
mass = moles x molar mass
Also, note that the number of atoms/molecules in a sample is the moles of the sample x Avogadro's number (6.02 x 10^23)
If we rearrange the equation for moles, we would get:
moles = molecules of sample/6.02 x 10^23
Plug in the values for the equation above to get the moles:
moles = (3.408 x 10^21)/(6.02 x 10^23)
moles = 0.00566112956 (we're not done yet)
Now that we have the moles and we were already provided the molar mass, we can calculate the mass using the very first equation we rearranged.
mass = moles x molar mass
mass = 0.00566112956 x 44.01
mass = 0.2491g (answered 4 places past the decimal point)
Therefore the sample of Carbon Dioxide has a mass of 0.2491g
50 PTS!!!!! Please answer without links!
What type of chemical reaction happens with Aerobic Cellular Respiration?
Synthesis, decomposition, single displacement, double displacement, or combustion.
What you see as you look up at the night sky depends on the weather, the time of year, your location, and how dark your surroundings are. The
---
and stars are the celestial objects most people can see in the night sky.
the [moon] and stars are what most people see.
