Answer: 7 valence electrons
Explanation:
Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.
The electrons are filled according to Afbau's rule in order of increasing energies.
Valence electrons are the number of electrons constituting the outermost shell of an atom.
Thus the electronic configuration could be :
[tex]1s^22s^22p^5[/tex]
Thus the outermost orbit is 2 which has (2+5)= 7 electrons. Thus there are 7 valence electrons.
Please help me thanks so much?!?.:;)...I’ll mark you.:;)))
Answer:
physical
Explanation:
If you have a gas sample with an initial pressure of 4 atm and a volume of 550 L, what will the final volume be if you change the pressure to 2.3 atm?
Answer:
V₂ = 956.52 L
Explanation:
Given data:
Initial pressure = 4 atm
Initial volume = 550 L
Final volume = ?
Final pressure = 2.3 atm
Solution:
The given problem will be solved through the Boyle's law,
"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"
Mathematical expression:
P₁V₁ = P₂V₂
P₁ = Initial pressure
V₁ = initial volume
P₂ = final pressure
V₂ = final volume
Now we will put the values in formula,
P₁V₁ = P₂V₂
4 atm × 550 L = 2.3 atm × V₂
V₂ = 2200 atm. L/ 2.3 atm
V₂ = 956.52 L
What is the mass of 4.42 cm3 of platinum? The density of platinum is 22.5 g/cm3. (Sig Fig rules + units)
Answer: 99.45 g
Explanation: we have 22.5 g of Platinum in every 1cm3 of Platinum so if we take 4.42 cm3 of Platinum we will have 4.42 × 22.5 g = 99.45 g of Platinum
KCI is a molecule. True or False
Answer: duh
Explanation:
how many grams from a 100 grams sample of fe2o3 is iron
Answer:
40 Grams
Explanation:
Fe2O3 is 2 parts Iron 3 parts Oxygen.
Assuming the molecular weights of both are equivalent (ideal elemental law), it is a 2:3 ratio, or 2/5 of the total.
2/5 of 100 is 40, so the answer is
40 grams
A student working in the laboratory produces 6.81 grams of calcium oxide, CaO, from 20.7 grams of calcium
carbonate, CaCO3, according to the reaction CaCO3 → CaO + CO2. Calculate the theoretical yield and
the percent yield for the reaction. Show and/or explain your work.
Answer:
Percent yield = 57.8 %
Theoretical yield = 11.781 g
Explanation:
Given data:
Mass of CaO produced = 6.81 g
Mass of CaCO₃ react = 20.7 g
Theoretical yield = ?
Percent yield = ?
Solution:
Chemical equation:
CaCO₃ → CaO + CO₂
Number of moles of CaCO₃ :
Number of moles = mass/molar mass
Number of moles = 20.7 g/ 100.1 g/mol
Number of moles = 0.21 mol
Now we will compare the moles of CaCO₃ with CaO.
CaCO₃ : CaO
1 : 1
0.21 : 0.21
Theoretical yield of CaO:
Mass = number of moles × molar mass
Mass = 0.21 mol × 56.1 g/mol
Mass = 11.781 g
Percent yield:
Percent yield = ( actual yield / theoretical yield ) × 100
Percent yield = (6.81 g/ 11.781 g) × 100
Percent yield = 57.8 %
What is the degree of sugar dissociation?
Answer: Na+ (8%)
Explanation:
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Answer:
I did
Explanation:
Which of the following is true of a balanced chemical equation?
A) The total number of molecules of reactants has to be the same as the total number of product molecules
B) the total number of atoms in the reactant molecules doesn't have to equal the total number of atoms in the product molecules
C) The identity of the atoms in the reactants has to be the same as the identity of the atoms in the products
D) The physical state of the reactants has to be the same as the physical state of the products
Answer:
A) The total number of molecules of reactants has to be the same as the total number of product molecules
Explanation:
In chemistry, a chemical equation consists of reactants and products. The reactants are the compounds/substances that chemically combine to give rise to the products. According to the law of conservation of mass, a chemical equation needs to be BALANCED.
A chemical equation is said to be BALANCED when the number of atoms/molecules on the reactant side is equal to that on the product side. In other words, total number of molecules of reactants has to be the same as the total number of product molecules
How many moles are equal to 13.25 g of water, H2O?
Answer:
0.736 moles
Explanation:
mole = mass/molecular mass
mole of H2O = 13.25/18.0
mole of H2O = 0.736
After sugar dissolves in water, the sugar is no
longer visible. The mixture tastes sweet so
you know the sugar is still there.
Why can't you see the sugar anymore?
Justify your answer.
Answer:
Because it devolved
Explanation:
The sugar can no longer be seen because upon solubilization;
A large collection of sugar molecules break into individual molecules and disperse in the water. Additionally, the lattices of the crystalline sugar has been broken, consequently, rendering the sugar soluble in water.Definition:
Solubility is characterized by the formation of new bonds between the solute molecules and solvent molecules.
In this case; the solute is sugar while the solvent is Water.
PS: The mixture formed from sugar and water is called Sugar syrup.
Read more:
https://brainly.com/question/24671587
Create brown bunnies and white bunnies together
with a brown background.
After 2 generations add wolves.
What happens to the bunnies?
PLS ANSWER
Answer:
I don't know exactly how you want me to answer but I feel like the white bunnies population decrease because the brown bunnies have an advantage with the brown background so the wolves will hunt and kill all the white ones because they are more standing out.
Answer:
If you are thinking all the white bunnies would be gone that would not happen
Explanation:
If you put white bunnies with the withe the brown bunnies they would breed so then there would be more bunnies then there would be more bunnies and wolves.
Which statement describes a similarity between conductors and insulators?
They both allow for the free flow of electrons between atoms.
They can both be made without matter.
They both involve high resistance to electrical charge.
They can both be used in an electric circuit.
Answer:
They can both be used in an electric circuit.
Explanation:
Though conductors and insulators are very different from each other but still they have a similarity that "they can both be used in an electric circuit".
Conductors are the material that allows electricity to flow and insulators have high resistance and do not allow electricity to flow.
Both conductors and insulators are used in an electric circuit as conductor is used in wires, batteries and bulb to flow current while insulators are used in insulation of wire, switches, plugs and etc. Combination of them makes the circuit shock free.
Hence, the correct answer is "They can both be used in an electric circuit."
Answer:
They can both be used in an electric circuit.
Explanation:
I need help asap please help me
Answer:
it says the answer is variation
if you move 60 meter in 10 seconds, what is your speed
the answer was S=d/t = 60/10 = 6m/s, I'm sorry for getting it wrong the first time I answered ^^
standard form to scientific notation: 0.004078

4. How many moles of oxygen gas are needed to react completely with
3.0 moles of C2,H6.?
Hey there!:
Mole ratio :
2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O
2 moles C₂H₆ -------------------- 7 moles O₂
3.0 moles C₂H₆ ------------------ moles O₂ ??
moles O₂ = 3.0 x 7 / 2
moles O₂ = 21 / 2
moles O₂ = 10.5 moles of O₂
Hope this helps!
What are some ways to prevent heat energy loss in matter?
Answer:
Use less heat in your house.
Explanation:
You have blankets in your house, huddle up for a good movie together.
Answer:
Simple ways to reduce heat loss include
Heat loss through windows can be reduced by using double glazing
Heat loss through walls can be reduced using cavity wall insulation
Heat loss through the roof can be reduced by laying loft insulation
Explanation:
Why is solid potassium chloride a not good conductor of electricity
Answer:
The charge carriers can be electrons, as in metals, or positive and negative ions in the case of ionic (or electrolytic) conductors. In a crystalline solid, the potassium and chlorine atoms are ionically-bonded within a crystalline matrix that prevents them from easily moving.
Explanation:
can u pls help me with this question
can u pls help me with this question
Answer:
B
Explanation:
PLEASE ANSWER: The density of a gas at STP is 0.75 g/L. What is the mass of this gas?
Answer:
the mass of the glass is 2
10. All atoms of the same element have the same______
O number of neutrons
O mass numbers
O number of protons
O mass
Question 6 (1 point)
Hydrogen gas and nitrogen gas can react to form ammonia according to this equation: N2 (g) + m 3H2 (g) --> 2NH3(g) How many liters of nitrogen gas are required to produce 4 moles of NH3 (g)? Assume conditions of standard temperature and pressure (STP). Hint: One mole of gas occupies 22.4 liters under standard conditions of temperature and pressure (STP).
Answer:
44.8 L of N₂.
Explanation:
We'll begin by writing the balanced equation for the. This is illustrated below:
N₂ + 3H₂ —> 2NH₃
From the balanced equation above,
1 mole of N₂ reacted to produce 2 moles of NH₃.
Therefore, Xmol of N₂ will react to produce 4 moles of NH₃ i.e
Xmol of N₂ = (1 × 4)/2
Xmol of N₂ = 2 moles
Thus, 2 moles of N₂ reacted to produce 4 moles of NH₃.
Finally, we shall determine the volume of N₂ required for the reaction. This can be obtained as follow:
1 mole of N₂ occupies 22.4 L at STP.
Therefore, 2 moles of N₂ will occupy = (2 × 22.4) = 44.8 L
Thus, 44.8 L of N₂ is needed to produce 4 moles of NH₃.
Two Balloons one filled with hydrogen gas and second filled with neon gas. what gas should be used in an experiement to identify the element in each balloon?
Answer:
Oxygen
Explanation:
If two balloons are filled with hydrogen gas and helium gas respectively, then we want to identify what gas is in each balloon, we have to do so by exposing the both balloons to flame in an oxygen atmosphere.
Hydrogen combines with oxygen in the presence of a flame with quite a loud sound and the flame is sustained but when a flame is brought near helium gas in a balloon, the gas will only make a little sound when exposed to the flame and extinguish the flame.
The reason for the explosion of the gas in the hydrogen balloon is that combustion of hydrogen gas is exothermic. The heating up of surrounding air molecules leads to a sudden explosion.
However, the helium balloon makes a little sound when the balloon is ruptured releasing helium gas which extinguishes the flame.
F O R 50 P O I N T S !!!
Give the exact quantum numbers of:
1. 11th electron in 5f14
2. 8th electron in 4d10
3. 5th electron in 4p6
4. 15th electron of phosphorus
5. Last electron of Neptunium
Answer:
You would put the 4 quantum numbers corresponding to the electrons being described above
Explanation:
Quantum numbers refer to electrons, so I'll assume you mean the electron number that would correspond with the atomic number of the element. Quantum numbers are basically like an address for electrons, giving us information about the location of an electron from most general to most specific.
The quantum selection rules allow finding the results for the quantum numbers for each electrons are:
1. n = 5, f l = 3 el m = 1
The quantum number of spin. Opposite the first electrons.
2. n = 4, l = 2, m = 0
Spin opposite the first electrons.
3. n = 4, l = 1, m = 0
Spin number opposite the first electrons.
4. n = 3, l = 1, m = 1
Spin all electrons have the same spin.
5. n = 7, l = 2, m = 0
Spin quantum number two electrons with opposite spin.
The solution of the Scrodinger's equation in three dimensions results have three constants related, these constants are called quantum numbers.
Principal (n). Determines the energy of the electron and has values from zero to infinity. Secondary or orbital (l). Determines the shape of the orbitals and has values from zero to (n-1), in general letters are used for their representation for the values 0,1, 2, 3 the symbols are used: s, p, d, f. Magnetic (m). It corresponds to the magnetic moment due to the movement of the electron around the nucleus. It can have values from -l to l.
In independent experiments, a fourth quantum number called the spin magnetic moment was found, it can have two values + ½ and - ½
The rules for valid combinations of these quantum numbers are called selection rules, the spectroscope notation for each electron is.
[tex]n l ^m[/tex]
Where n is the principal number, l the orbital and m the magnetic.
To determine the value of the spin quantum number, the Pauli exclusion principle is used, which establishes that you cannot have two fermions (electrons) in the same quantum state, this deteriorates that in a state there can only be two electrons, one with upward spin and the other spin down.
Let's find the combination of these constants for each case.
1. The 11th electron of level 5f¹⁴.
The principal quantum number n = 5
Orbital quantum number f, l = 3
In the f orbital, a maximum of 14 electrons can be placed, since it has 7 sub-levels and according to the Pauli Exclusion principle, each one can have two electrons.
We place 1 electron in each sub-level and then we place a second electron with the opposite spin, therefore when we get to electron number 11 it has a spin opposite to that of the first 7 electrons, but there is no way to previously know its value.
we construct a table with the distribution of electrons.
Quantum number Electrons
n = 5
l = 0
l = 1
l = 2
l = 3
m = -3 ½ - ½
m = -2 ½ - ½
m = -1 ½ - ½
m = 0 ½ - ½
m = 1 ½
m = 2 ½
m = 3 ½
With the help of this table the other numbers are:
Tthe magnetic quantum number is m = 1
The quantum number of spin. opposite the spin of the first electrons.
2. The eighth electron of the 4d¹⁰ state
Pricipal number n = 4
Orbital number l = 2
We construct a table with the distribution of electrons.
Quantum number Electrons
n = 4
l = 0
l = 1
l = 2
m = -2 ½ - ½
m = -1 ½ - ½
m = 0 ½ - ½
m = 1 ½
m = 2 ½
With this table the other quantum numbers are;
Magnetic m = 0
Spin opposite the first electron
3. 5th electron of 4p⁶
Principal number n = 4
Orbital number p l = 1
We construct a table with the distribution of electrons.
Quantum number Electrons
n = 4
l = 0
l = 1
m = -1 ½ - ½
m = 0 ½ - ½
m = 1 ½
Magnetic number m = 0
Spin number opposite the first electrons.
4. 15th electron of phosphorus
The electron configuration of phosphor is
1s² 2s²2p⁶ 3s²3p³
Principal quantum number n = 3
Orbital quantum number p, l = 1
We construct the electron distribution table.
Quantum number electrons
n = 3
l = 0
l = 1
m = -1 ½
m = 0 ½
m = 1 ½
The other quantified numbers are:
Magnetic m = 1
Spin all electrons have the same spin.
5. The last electron of neptunium.
Electronic configuration.
Radon Gas Configuration + 5f⁴6d¹ 7s²
Principal quantum number n = 7
Orbital quantum number l = 2
Magnetic quantum number m = 0
Spin quantum number two electrons with opposite spin.
In conclusion using the quantum selection rules can determine the quantum numbers for each given electron are:
1. n = 5, f l = 3 el m = 1
The quantum number of spin. Opposite the first electrons.
2. n = 4, l = 2, m = 0
Spin opposite the first electrons
3. n = 4, l = 1, m = 0
Spin number opposite the first electrons.
4. n = 3, l = 1, m = 1
Spin all electrons have the same spin
5. n = 7, l = 2, m = 0
Spin quantum number two electrons with opposite spin.
Learn more about the quantum selection rules here: brainly.com/question/14288557
Suppose you are collecting a gas over water at 23 oC and obtain a pressure reading of 785.8 mm Hg. If the vapor pressure of water is 21.1 mm Hg at the collection temperature, what is the pressure of the collected gas
Answer:
764.7 mmHg
Explanation:
Step 1: Given data
Total pressure of the gaseous mixture (P): 785.8 mmHgPartial pressure of water vapor (pH₂O): 21.1 mmHgPartial pressure of the gas collected (pGas): ?Step 2: Calculate the partial pressure of the gas collected
The total pressure of the gaseous mixture is equal to the sum of the gas collected and the water vapor.
P = pH₂O + pGas
pGas = P - pH₂O
pGas = 785.8 mmHg - 21.1 mmHg = 764.7 mmHg
g Give the electron configurations for the following atoms. Do not use the noble gas notation. Write out the complete electron configuration. Example: Mg 1s22s22p63s2 Element Electron configuration Ne Li N S Sc
Answer: [tex]Ne:1s^22s^22p^6[/tex]
[tex]Li:1s^22s^1[/tex]
[tex]N:1s^22s^22p^3[/tex]
[tex]S:1s^22s^22p^63s^23p^4[/tex]
[tex]Sc:1s^22s^22p^63s^23p^64s^23d^1[/tex]
Explanation:
Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom. The electrons are filled according to Afbau's rule in order of increasing energies.
The electronic configuration for given elements is as follows:
[tex]Ne:10:1s^22s^22p^6[/tex]
[tex]Li:3:1s^22s^1[/tex]
[tex]N:7:1s^22s^22p^3[/tex]
[tex]S:16:1s^22s^22p^63s^23p^4[/tex]
[tex]Sc:21:1s^22s^22p^63s^23p^64s^23d^1[/tex]
Under certain conditions, the substance calcium carbonate can be broken down to form calcium oxide and carbon dioxide. If 31.7 grams of calcium carbonate react to form 17.8 grams of calcium oxide, how many grams of carbon dioxide must simultaneously be formed
Answer:
[tex]13.93\ \text{g}[/tex]
Explanation:
Molecular weight of [tex]CaCO_3[/tex] = 100.0869 g/mol
Mass of [tex]CaCO_3[/tex] = 31.7 g
Moles of [tex]CaCO_3[/tex] = [tex]\dfrac{31.7}{100.0869}=0.3167\ \text{mol}[/tex]
Moles of both [tex]CaO[/tex] and [tex]CO_2[/tex] is [tex]0.3167\ \text{mol}[/tex]
Molecular weight of [tex]CO_2[/tex] = 44 g/mol
Mass of [tex]CO_2[/tex] = [tex]44\times 0.3167=13.93\ \text{g}[/tex]
The mass of carbon dioxide formed simultaneously is [tex]13.93\ \text{g}[/tex].
Liquid gasoline is heated and becomes gasoline vapor. The gasoline vapor is then ignited by a spark, causing a fire. The entire process is: Group of answer choices
Answer: First an endothermic and then followed by the exothermic process
Explanation:
Based on the information given in the question, we should note that the entire process is an endothermic process at first and then an exothermic process.
We should note that heat is absorbed during an endothermic process and the environment is cooled but for an exothermic process, heat is being released which leads to the increase in the temperature of the surroundings.
