Answer:
45.0
Explanation:
Using the rules of rounding, we can round 44.981 to 45. We need that third sig fig though, so we add the trailing zero
The value 44.981 g to three significant figures is 45.0 g.
Significant figures, also known as significant digits, are the digits in a number that carries meaning in terms of precision and accuracy. They indicate the certainty or reliability of a measurement or calculated value.
To round the value 44.981 g to three significant figures, follow the rules for significant figures:
Identify the three most significant digits in the number. They are 4, 4, and 9.
Look at the digit immediately after the third significant digit. If it is 5 or greater, round up; if it is less than 5, round down.
In 44.981 g, the digit immediately after the third significant digit (9) is 8. Since 8 is greater than 5, round up.
Therefore, rounding 44.981 g to three significant figures gives us:
45.0 g.
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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.)
Which option(s) correctly shows an anion? Select all that apply.
Answer:
x
Explanation:
becaue neutron equal to mass num -atomic num
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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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
A conclusion in science states whether or not a hypothesis is correct
or not?
Answer:it do not states
Explanation:
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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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
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)
Active and inactive volcano in philipines?
355 volcanoes in the Philippines are inactive.
24 volcanoes are active
Answer:
TAAL ACTIVE
MAOUNT BALUGAO INACTIVE
Explanation:
CHEMISTRY! 50 POINTS! What is the original pressure of 20.0L of compressed gas if the pressure changes to 560.0mmHg when the volume is decreased to 15700mL?
Answer:
The answer is 439.60 mmHgExplanation:
To find the original pressure we use the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
Since we are finding the original pressure
[tex]P_1 = \frac{P_2V_2}{V_1} \\[/tex]
From the question
V1 = 20 L = 20,000 mL
P2 = 560.0mmHg
V2 = 15700mL
We have
[tex]P_1 = \frac{560 \times 15700}{20000} = \frac{8792000}{20000} = \frac{2198}{5 } \\ [/tex]
We have the final answer as
439.60 mmHgHope this helps you
4. Solve the following heat flow problem, being sure to show all your work (you may either type your
work or insert an image): Find the specific heat of 402 grams of graphite that absorbs 1136) of heat
energy as it changes temperature from 26°C to 30°C.
Answer should be 0.7J/gC
Answer:
0.70 J/g.°C
Explanation:
Step 1: Given data
Mass of graphite (m): 402 gHeat absorbed (Q): 1136 JInitial temperature: 26°CFinal temperature: 30 °CSpecific heat of graphite (c): ?Step 2: Calculate the specific heat of graphite
We will use the following expression.
Q = c × m × ΔT
c = Q / m × ΔT
c = 1136 J / 402 g × (30°C - 26°C)
c = 0.70 J/g.°C
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
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
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 many oxygen atoms are there in six dinitrogen monoxide molecules? express your answer as an integer
Answer:
6 oxygen atoms
Explanation:
Step 1: Given data
Number of dinitrogen monoxide molecules (N₂O): 6
Number of oxygen atoms (O): ?
Step 2: Calculate the appropriate ratio
The ratio of dinitrogen monoxide molecules to oxygen atoms is 1:1.
Step 3: Use the ratio to calculate the number of oxygen atoms
6 molecule N₂O × (1 atom O/1 molecule N₂O): 6 atom O
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 are they waiting? or what are their waiting?
please correct me if I'm wrong
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)
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 :)
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.
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 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:
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.
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.
Which best describes the purpose of a controlled experiment?
to make sure the results of the experiment support the hypothesis
to prevent a dangerous condition resulting from a reaction
to examine whether one variable causes a change in another
to prevent an undesired change in a variable
Answer: To examine whether one variable causes a change in another
Explanation:
Marcy tests a solution with a strip of blue litmus paper. The paper turns red. The solution is _____.
acidic
basic
neutral
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
What happens during a chemical reaction? Where do the reactants go, and where do the products come from?
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:
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
