Answer:
Rb = +1 , Sr = +2, In= +3, Sn = +4, Sb= +5
Explanation:
Formula:
Zeff = Z - S
Z = atomic number
S = number of core shell or inner shell electrons
For Sn:
Electronic configuration:
Sn₅₀ = [Kr] 4d¹⁰ 5s² 5p²
Zeff = Z - S
Zeff = 50 - 46
Zeff = +4
For Rb:
Electronic configuration:
Rb₃₇ = [Kr] 5s¹
Zeff = Z - S
Zeff = 37 - 36
Zeff = +1
For Sb:
Electronic configuration:
Sb₅₁ = [Kr] 4d¹⁰ 5s² 5p³
Zeff = Z - S
Zeff = 51 - 46
Zeff = +5
For In:
Electronic configuration:
In₄₉ = [Kr] 4d¹⁰ 5s² 5p¹
Zeff = Z - S
Zeff = 49 - 46
Zeff = +3
For Sr:
Electronic configuration:
Sr₃₈= [Kr] 5s²
Zeff = Z - S
Zeff = 38 - 36
Zeff = +2
What is the density of Radon (Rn) gas at a temperature of 100°C and a pressure of 0.75
atm?
Answer:
Density of Radon is 5.44 g/.
Explanation:
Given data:
Temperature of gas = 100°C (273+100 = 373 K)
Pressure of gas = 0.75 atm
Density of gas = ?
Solution:
First of all we will derive the formula.
We know that,
PV = nRT
and
n = m/M (m = mass, M = molar mass)
PV = (m/M) RT
PVM = (m/M) RT ×M
PVM = mRT
PVM/V = mRT/V
PM = dRT (m/V = d)
Now we will put the values in formula:
Molar mass of Radon is 222 g/mol .
0.75 atm ×222 g/mol = d× 0.0821 atm.L/mol.K ×373 K
166.5 atm.g/mol = d×30.62 atm.L/mol
d = 166.5 atm.g/mol / 30.62 atm.L/mol
d = 5.44 g/L
What is the molar mass of an unknown gas with a density of 2.00g/L at 1.00 atm and 25.0C
Answer:
Explanation:1. A 2.650-g sample of a gas occupies a volume of 428 mL at 0.9767 atm and 297.3 K. What is its molar mass?
2.
a. A sample of nitrogen gas has a volume of 10.0 L at 2.50atm and 50.0℃. If the pressure is increased to 5.00 atm and the temperature decreases to 25.0℃, what volume does the gas occupy?
(a). 5.00L, (b).4.61L, (c).2.50L, (d).5.42L
b. Using the average bond energy, calculate the enthalpy of the above reaction. draw Lewis structures of the reactants and products first to determine the exact bond order. N2(g)+3H2(g)→2NH3(g)
What changes a liquid to a gas?
Answer:
evaporation
Explanation:
Answer:
boiling (or vaporization)
Explanation:
At a certain temperature, the particles in a liquid have enough energy to become a gas. This process of a liquid becoming a gas is called boiling (or vaporization.)
What happens during a chemical reaction? Where do the reactants go, and where do the products come from?
True or False: A chemical reaction ALWAYS results in a ne product being formed
Answer:
True
Explanation:
A chemical reaction will always result in a new product or substance being formed
that is what makes it a chemical reaction.
A conclusion in science states whether or not a hypothesis is correct
or not?
Answer:it do not states
Explanation:
Calculate the molarity of a solution prepared by dissolving 0.20 mol of KNO3 into enough water to make 250 mL of solution. ______ M
Answer:
0.8M
Explanation:
Given parameters:
Number of moles of KNO₃ = 0.2mol
Volume of KNO₃ = 250mL
Unknown:
Molarity of the solution = ?
Solution:
The molarity of a solution is the number of moles in a given volume of a solution;
Molarity = [tex]\frac{number of moles }{volume}[/tex]
We need to convert the given volume to L;
1000mL = 1L
250mL will give 250 x 10⁻³L = 0.25L
So;
Molarity = [tex]\frac{0.2}{0.25}[/tex] = 0.8M
Answer:
0.8 M
Explanation:
The formula is mol divided by liters. Converting 250 ml to .25 liters is important. Dividing .2 by .25 gets the answer. (I swear it’s right but it’s graded wrong so take this with a grain of salt)
What is the energy of a photon of red light having a frequency of 3.08 x 10^14 HZ?
Answer:
2.04 x 10⁻¹⁹J
Explanation:
Given parameters:
Frequency = 3.08 x 10¹⁴Hz
Unknown:
The energy of the photon = ?
Solution:
The energy of a photon is given as;
E = hf
Where h is the planck's constant
f is the frequency
Insert the parameters and solve;
E = 6.63 x 10⁻³⁴ x 3.08 x 10¹⁴
E = 20.4 x 10⁻³⁴⁺¹⁴
E = 20.4 x 10⁻²⁰ = 2.04 x 10⁻¹⁹J
Answer:
2.97*10-19 j
Explanation:
E=Energy of photon
H=Planck constant=6.626*10-34
V=Frequency of photon
we can plug what we already know E=(6.626*10-34)(4.48*10 14)
Danielle is asked to determine the density and the identity of a metal. She determines the mass of the metal to be 102.06g and then determines the volume of the sample using water displacement. Find the density. Round the answer to the nearest whole number?
Answer:
11 g/mL
Explanation:
From the question given above, the following data were obtained:
Mass of metal = 102.06 g
Volume of water = 38 mL
Volume of water + metal = 47 mL
Density of metal =.?
Next, we shall determine the volume of the metal. This can be obtained as shown below:
Volume of water = 38 mL
Volume of water + metal = 47 mL
Volume of metal =..?
Volume of metal = (Volume of water + metal) – (Volume of water)
Volume of metal = 47 – 38
Volume of metal = 9 mL
Finally, we shall determine the density of the metal as follow:
Mass of metal = 102.06 g
Volume of metal = 9 mL
Density of metal =.?
Density = mass /volume
Density of metal = 102.06 / 9
Density of metal = 11.34 ≈ 11 g/mL
Therefore, the density of the metal is 11 g/mL
2.54 mL of ethanol to mol ethanol (Hint: the density of ethanol is 0.789
g/mL.)
0.04350179862
Explanation:
Make sure to check for sig figs though. Basically, you have 2.54 mL and you multiply that by the 0.789 g/mL and mL cancels out and you are left with 2.00406g. There are 46.06844 grams per mol of ethanol, so to cancel out grams we multiply by 1/46.06844. And then we are left with 0.04350179862 mol
How many moles of Nitrogen in 40.0 g of N2O?
.14 g
25.5 g
14.5 g
Answer:
To do this question. we first have to find the mass% of nitrogen in N2O and then, using that percentage, we can simply find the number of moles of N from the number of moles of N2O
Mass % of Nitrogen:
Mass% of nitrogen = (Molar mass of N2 / Molar mass of N2O)*100
Mass% nitrogen = (28 / 44)*100
Mass% of Nitrogen = 0.63 * 100
Mass% nitrogen = 63%
Mass of Nitrogen:
So, now we can say that in any given mass of N2O. 63% of the total mass is the mass of Nitrogen
Hence, total mass * 63/100 = Mass of Nitrogen
Replacing the variables
40 * 0.63 = Mass of Nitrogen
Mass of Nitrogen = 25.2 grams
PLZ HELP PLZ HELP HURRY 40 POINTS NO WRONG ANSWERS PLZ
what are they waiting? or what are their waiting?
please correct me if I'm wrong
A lead ball has a mass of 5.910 g and a diameter of 10.0 mm. What is the density of lead in grams per cubic centimeter
Answer:
Explanation:
The formula is density = mass÷volume
Values given are:
mass = 5.910g and
diameter = 10.0 mm = 1cm
so, we need to find the volume first.
Volume of a sphere is (4/3)πr³
thus, V = 4.189 cm³
Density = mass ÷ volume
density = 5.910 ÷ 4.189
= 1.411 g/cm³
Your big brother has been bragging about how he can bench press 4,000 grams at the gym. Sounds impressive, but you know better. Use your skills to find how many pounds of weight he is actually pressing.
A brother is bragging about doing a bench press of 4000 grams at the gym. 4000 grams is equal to 8.818 pounds.
What is a bench press?The bench press or chest press is training or weight training to strengthen your arm and chest muscles. It is done by laying down on a bench and pushing and pulling up the bars with weight.
It is a common weight-lifting exercise in gyms. Trainers use accordingly weight on the basis of the trainee's weight and strength that is doing the bench press, and the weight is measured differently in different countries. Eight-pound is not a very big amount.
In America, weight is measured in pounds, one kg is 1000 grams and
1 gram is 0.00220462
4000 x 0.00220462
4000 grams will be 8.818 pounds.
Thus, 4000 grams is equal to 8.818 pounds.
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Which will have both the highest ionization energy and the largest atomic
radius? Potassium, Bromine, Krypton
Answer:
Bromine
Explanation:
Cuz it has bro in it :)
How do changes in population size relate to environmental conditions?
Answer:
No simple relationship exists between population size and environmental change. However, as global population continues to grow, limits on such global resources as arable land, potable water, forests, and fisheries have come into sharper focus.
Explanation:
X-ray crystallography is used to see the structure of molecules. Scientists have used this technique to find the structure of cholesterol, an important biological molecule.
Knowledge of the structure of cholesterol is helpful because it may affect
A. how cholesterol works in the body.
B. the amount of cholesterol that is considered healthy.
C. previous ideas about which foods contain cholesterol.
D. previous explanations of how cholesterol works in the body.
Answer:
A. how cholesterol works in the body.
Explanation:
If we know the precise structure of a molecule (by X-ray crystallography), we can understand more about how it interacts with cells, proteins, and other molecules. It can also tell us what reactions it might take part in.
Therefore, we can learn more about how it works in the body and what activities it takes part in in the cells of the body.
Answer:
A
Explanation:
nuityyy
which element would be used to help support a building
C
He
Na
Fe
Which of the statements below about buoyancy is true?
A.if the buoyant force is greater than the force of gravity,the object will sink
B.buoyancy is a force that acts on objects that are placed in a fluid
C.all objects that experience the force of buoyancy float
D.buoyancy pushes objects down in the same direction as gravity
(answer asap plz I will give brainliest to who helps me )
Answer:
it's A. if the force of gravity is greater than the buoyant force, the object will sink.
Explanation:
just took the quiz on a p e x
how would you represent a sulfur isotope that contains 18 neutrons using the format
Answer:
S–34
Explanation:
From the question given above, the following data were obtained:
Neutron number = 18
The isotope of sulphur still retains its atomic number of 16.
Recall:
Atomic number = proton number
Atomic number of sulphur (S) = 16
Therefore,
Proton number = 16
Next, we shall determine the mass number of the sulphur isotope. This can be obtained as follow:
Proton number = 16
Neutron number = 18
Mass number =.?
Mass number = Proton + Neutron
Mass number = 16 + 18
Mass number = 34
The symbol for sulphur is S.
Thus, the symbol of sulfur isotope that contains 18 neutrons is S–34
This is how manganese appears in the periodic table.
What is the arrow is pointing to?
period symbol of manganese
isotope symbol of manganese
group symbol of manganese
atomic symbol of manganese
Answer:d
Explanation:took the test
The arrow in the statement is likely pointing to the atomic symbol of manganese, which is the letter "Mn." Therefore, option (D) is correct.
In the periodic table, elements are organized based on their atomic number, which corresponds to the number of protons in the nucleus of an atom. Manganese has an atomic number of 25, indicating that it has 25 protons. The atomic symbol is a shorthand representation of the element's name, allowing for easy identification and reference.
Therefore, the arrow is pointing to the atomic symbol of manganese, "Mn," indicating its position in the periodic table and distinguishing it from other elements. The atomic symbol is a fundamental component of the periodic table, enabling scientists to communicate and study elements and their properties more efficiently.
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Active and inactive volcano in philipines?
355 volcanoes in the Philippines are inactive.
24 volcanoes are active
Answer:
TAAL ACTIVE
MAOUNT BALUGAO INACTIVE
Explanation:
Carbon dioxide is in a steel tank at 20C 10 liters and 1 atm. What is the pressure on the gas when the tank is heated to 100C?
Answer:
1.273 atm
Explanation:
We are given:
P1 = 1 atm P2 = x atm
T1 = 20 degree celsius or 293 k T2 = 100 degree celsius OR 373 k
Since the volume remains constant, we don't have to talk about that
From the Gas equation:
PV = nRT
Since number of moles (n) , Universal gas constant (R) , Volume of the gas (V) are constants
P / T = k (where k is a constant)
Hence we can say that P1 / T1 = k --------------(1)
Also, P2 / T2 = k -------------------------------------(2)
where k is the same constant
From (1) and (2):
P1 / T1 = P2 / T2
Now, plugging the values in this equation
1 / 293 = x / 373
x = 373 / 293
x = 1.273 atm
Therefore, the pressure of CO2 after increasing the temperature to 100 degree celsius is 1.273 atm
At STP, a 50-gram sample of H20(I) and a 100-gram sample of H20(I) have
Answer:
(1) the same chemical properties .
Explanation:
Hello!
In this case, among the options:
(1) the same chemical properties
(2) the same volume
(3) different temperatures
(4) different empirical formulas
We can see that they have the same chemical properties as they at the same conditions, same type of bond (polar), molecular geometry, bond angle (104.5 °) and so on. Nevertheless, at STP (1 atm and 273.15 K) they do not have the same volume since the larger the mass, the larger the volume, they have the same temperature and the both of them are H₂O.
It means that the answer is (1) the same chemical properties .
Best regards.
Selenium-81 has an abundance of 21.91% and a mass of 80.65 amu.
Selenium-84 has an abundance of 23.35% and a mass of 83.67 amu.
Selenium-80 has an abundance of 54.74% and a mass of 79.64 amu.
What is the average atomic mass of Selenium according to these values?
Answer:
80.80amu
Explanation:
multiple each value by its percentage (in decimal form) and take the sum.
80.65x.2191 + 83.67x.2335 + 79.64x.5474 = 80.802296 sig figs = 80.80
A compound is found to contain 40.05 % sulfur and 59.95 % oxygen by mass.
The empirical formula for this compound is
Answer:
im not good at chem
Explanation:
sorry bro
The empirical formula for the compound containing 40.05 % sulfur and 59.95 % oxygen is SO₃
Data obtained from the question Sulphur (S) = 40.05%Oxygen (O) = 59.95%Empirical formula =? How to determine the empirical formulaThe empirical formula of the compound can be obtained as follow
Divide by their molar mass
S = 40.05 / 32 = 1.25
O = 59.95 / 16 = 3.75
Divide by the smallest
S = 1.25 / 1.25 = 1
O = 3.75 / 1.25 = 3
Thus, the empirical formula of the compound is SO₃
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A solution contains 90 mL of methanol, 18 mL of propanol, and 2 mL of diethyl ether. Which is the solvent in this solution?
Answer:
Methanol
Explanation:
Marcy tests a solution with a strip of blue litmus paper. The paper turns red. The solution is _____.
acidic
basic
neutral
the male and female sex cells combine to form a
Answer:
zygote
Explanation:
In human beings, each gamete contains 23 chromosomes, half the number found in the other cells of the body. When the male and female gametes fuse, they become a zygote containing the full 46 chromosomes, half of which came from the father and half from the mother.
Answer:
zygote
Explanation:
In human beings, each gamete contains 23 chromosomes, half the number found in the other cells of the body. When the male and female gametes fuse, they become a zygote containing the full 46 chromosomes, half of which came from the father and half from the mother.
