Answer:
Explanation:
Purpose of Case Control Studies
To determine whether or not an association exists between a disease and a particular risk factor. To start with a group of people with disease and work back to see whether a possible risk factor may be the cause. It may be the first step in testing a hypothesis.
What is the Noble gas electron configuration of lead (Pb)?
ammonia gas occupies a volume of 57.9 L at a pressure of 532.4atm. if the pressure were lowered to 256.8atm,what would the new volume be
Answer:
683838447745 anmmlllkkkkk
The representative particle for NaF
Answer:
Na2S, it is the formula unit
Explanation:
The representative particle of CO2 is the molecule, while for Na2S, it is the formula unit
This is IXL pls hurry pls! SOS major
Answer:
the same as
Explanation:
that's what makes the most since to me but i may be wrong
as a rollercoaster goes downhiQuestion 2 options:
kinetic energy is converted into potential energy
potential energy is converted into kinetic energy
electrical energy is converted into potential energy
potential energy is converted into electrical energy
ll
Answer:
b potential hope this is right
If 0.813 g of O3 reacts with 0.605 g of NO, how many grams of NO2 will be produced?
Answer:
0.74 g O
3
=
48
0.74
=0.0154 mol O
3
0.67 g NO=
30
0.67
=0.0223 mol NO
O
3
is the limiting reagent and NO is in excess =0.0223−0.0154=0.007 mol
Thus, O
3
taken =NO
2
formed =0.0154 mol NO
2
=0.0154×46 g NO
2
Explanation:
What is the concentration of sodium ions in 0.185 M Na2CO3?
Answer:
0.370 M
Explanation:
Step 1: Given data
Molar concentration of the sodium carbonate solution: 0.185 M
Step 2: Write the balanced dissociation equation
Sodium carbonate is a strong electrolyte that dissociates according to the following equation.
Na₂CO₃(aq) ⇒ 2 Na⁺(aq) + CO₃²⁻(aq)
Step 3: Calculate the molar concentration of sodium ions
The molar ratio of Na₂CO₃ to Na⁺ is 1:2.
0.185 mol Na₂CO₃/L × 2 mol Na⁺/1 mol Na₂CO₃ = 0.370 mol Na⁺/L
Which two formulas are used to calculate potential and kinetic energy?
Answer:
[tex]\boxed{\bold { \large { \boxed {KE=\frac{1}{2} mv^2 \ , \ PE=mgh}}}}[/tex]
Explanation:
Kinetic energy formula
[tex]\displaystyle KE=\frac{1}{2} mv^2[/tex]
Potential energy formula
[tex]\displaystyle PE=mgh[/tex]
[tex]\displaystyle KE \Rightarrow \sf kinetic \ energy \ (J)[/tex]
[tex]\displaystyle PE \Rightarrow \sf potential \ energy \ (J)[/tex]
[tex]\displaystyle m \Rightarrow \sf mass \ (kg)[/tex]
[tex]\displaystyle v \Rightarrow \sf velocity \ (m/s)[/tex]
[tex]\displaystyle g \Rightarrow \sf acceleration \ of \ gravity\ (m/s^2)[/tex]
[tex]\displaystyle h \Rightarrow \sf height \ (m)[/tex]
NEED HELP ASPA WILL MAKE THE BRAINIEST ANSWER
A student captures 0.50
moles of hydrogen (H2), oxygen (O2), chlorine (Cl2), carbon dioscide (CO2), and carbon monoxide (CO) gas in separate, evacuated flasks.
Arrange the flasks of gases in order of increasing grams of gas.
.H
H
H2
H2
Answer: [tex]H_2[/tex] < [tex]CO[/tex] < [tex]O_2[/tex] < [tex]CO_2[/tex] < [tex]CL_2[/tex]
Explanation:
According to avogadro's law, 1 mole of every substanceweighs equal to its molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
1. Mass of [tex]H_2=moles\times {\text {Molar mass}}=0.50moles\times 2g/mol=1g[/tex]
2. Mass of [tex]O_2=moles\times {\text {Molar mass}}=0.50moles\times 32g/mol=16g[/tex]
3. Mass of [tex]Cl_2=moles\times {\text {Molar mass}}=0.50moles\times 71g/mol=35.5g[/tex]
4. Mass of [tex]CO_2=moles\times {\text {Molar mass}}=0.50moles\times 44g/mol=22g[/tex]
5. Mass of [tex]CO=moles\times {\text {Molar mass}}=0.50moles\times 28g/mol=14g[/tex]
Thus the flasks of gases in order of increasing grams of gas is:
[tex]H_2[/tex] < [tex]CO[/tex] < [tex]O_2[/tex] < [tex]CO_2[/tex] < [tex]CL_2[/tex]
What is weather?
a
The atmospheric conditions over many days, weeks, months, and years.
b
The atmospheric conditions for a particular moment in time.
c
The atmospheric conditions forecasted for the next season.
I need 11 12. 13. 14. 15. And 16 please and thank you ❤
Answer:
11.) Radio
12.) Microwave
13.) Infrared
14.) Ultraviolet
15.) X-Ray
16.) Gamma Ray
Radio waves have the longest wavelength, and gamma rays have the shortest wavelength.
Due to changes in the environment, having lighter-colored fur becomes a
survival advantage in a population of wolves.
What is most likely to happen in the next generation?
Answer:
There will be more light-colored wolves.
Explanation:
Evolution is based off the survival of those with the most advantages in the wild. Since their light coat gives them a survival advantage, they will reproduce more.
How many particles are in 1.43 g of a compound with a molar mass of 233? (No molar mass calculation needed) (show work plz)
Answer:
Explanation:
mol = given mols / molar mass
given mass = 1.43 grams
molar mass = 233
mols = 1.43 / 233 = 0.00614
1 mol contains 6.02 * 10^23 particles
0.00614 moles = x Cross multiply
1*x = 0.00614 * 6.02*10^23
x = 3,68 * 10^21 particles.
If 5.025 grams of NaOH are dissolved in 2.4 liters of water, what is the Molarity of the solution?
Answer:
0.052 M.
Explanation:
Hello!
In this case, since the molarity is computed by dividing the moles of the solute by the volume of the solution in liters (M=n/V), we first need to compute the moles in 5.025 grams of NaOH as shown below:
[tex]n=5.025g*\frac{1mol}{40.0g}\\\\n=0.126mol[/tex]
In such a way, we compute the molarity as show below:
[tex]M=\frac{0.126mol}{2.4L}\\\\M=0.052M[/tex]
Best regards!
Which kingdom contains both unicellular and multicellular eukaryotic organisms?
Animalia
Fungi
Plantae
Bacteria
what is is pls
Which statement best describes how an electromagnetic motor works?
Electrons are moved through a magnet, creating a circuit. That circuit interacts with a current, moving the
conductor in the orientation of the field
Electrons are moved through a current, creating a circuit. That circuit interacts with a magnet, moving the
conductor in the onentation of the field.
Elections are moved through a circuit, creating a current That current interacts with a magnet, moving the
conductor in the orientation of the field
Electrons are moved through a magnet creating a current. That current interacts with a circuit, moving the
conductor in the onentation of the field
Answer:
electrons are moved through a magnet creating a current. the current instracts with a circuit, moving the conductor in the onentation of the field
how does a decrease in potential energy during a chemical rwaction relate to the temperature of the surroundings
Answer: If the potential energy of the reaction system decreases, then kinetic energy in the surroundings increases and the temperature of the surroundings rises
Explanation:
The decrease in the potential energy results in an increase in the temperature of the system and surroundings.
Mechanical energy has been described as the sum of the kinetic and the potential energy in the system. With the increase in the potential energy, there has been a decrease in the kinetic energy and vice versa.
The decrease in the potential energy results in an increase in the kinetic energy of the system. The kinetic energy has been termed as the energy of performing work. The rise in the kinetic energy results in an increase in the work done in the system and there has been an increase in the temperature of the system.
Thus, the decrease in the potential energy results in an increase in the temperature of the system and surroundings.
For more information about the potential energy, refer to the link:
https://brainly.com/question/21288807
Most of Earth's major earthquakes are caused by
x
seasonal heating and cooling of Earth's surface
B
x
weathering of rock at Earth's surface
C
x
earth's gravitational attraction to the Moon
D
x
faulting of rock in earth's crust
Answer:
d
When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking that we feel.
A 18.5 gram sample of metal was added to a graduated cylinder that had
an initial volume of 45.50 mL. The water level raised to 54.10 mL. Using
this information, calculate the density of the metal. *
Answer:
[tex]d=2.15g/mL[/tex]
Explanation:
Hello there!
In this case, since the density of the metal is computed as shown below:
[tex]d=\frac{m}{V}[/tex]
We need to calculate the volume of the solid by subtracting the final volume and the initial volume of water:
[tex]V=54.10mL-45.50mL\\\\V=8.60mL[/tex]
Thus, we obtain:
[tex]d=\frac{18.5g}{8.60mL}\\\\d=2.15g/mL[/tex]
Best regards!
Solder is a silver metal used to hold pipes together. When the solder is heated, it melts and acts as a type of metal "glue." Mrs. Hanley heats a piece of solder until it melts between two pipes. What best identifies the point at which a physical change first takes place?
A)when the solder melts
B)when the solder cools down
C)when the solder is a soft metal
D)when the solder becomes solid again
Answer:
A
Explanation:
I need help ASAP pls the last question
Answer:When more gas particles enter a container, there is less space for the particles to spread out, and they become compressed. ... The particles exert more force on the interior volume of the container. This force is called pressure.
Explanation:
(CH3CH2)2CHCH(CH3)2 Check all that apply. Check all that apply. alkane alkene alkyne cycloalkane cycloalkene cycloalkyne aromatic hydrocarbon
Answer:
Alkane
Explanation:
Alkane is a class of organic compounds that contain only carbon and hydrogen and the carbon atoms are connected to each other by single bonds.
Now, if we look at the molecule whose condensed structural formula is shown in the question, we will notice that the compound can only contain single bonds. That is, the molecule is a saturated hydrocarbon(alkane).
I have drawn out the full structure of the compound to illustrate this point.
Radioactive decay follows first-order kinetics. If a sample of I-131 decays from 25.0 mg to 8.25 mg in 12.8 days, what is the rate constant, k?
Answer:
k = 0.0866 days⁻¹
Explanation:
The isotope decay of the atom follows the equation:
ln [A] = -kt + Ln[A]₀
Where [A] is the amount of the isotope after time t = 8.25mg
Time = 12.8days
k is rate constant
[A]₀ is actual amount of the isotope = 25.0mg
Replacing:
ln 8.25mg = -k*12.8days + ln 25.0mg
2.11 - 3.22 = -k*12.8days
-1.11 = -k12.8days
k = 0.0866 days⁻¹
How many moles are in 568 grams of Gold?
Why do not all rock types contain fossils?
Excessive heat and pressure can destroy fossils.
Fossils can only be created in certain places around the world.
Fossils cannot be created near volcanoes.
Fossils are too large to be found in igneous and metamorphic rocks.
Answer:
Igneous rocks form from molten rock, and rarely have fossils in them. Metamorphic rocks have been put under great pressure, heated, squashed or stretched, and fossils do not usually survive these extreme conditions. Generally it is only sedimentary rocks that
Explanation:
Hope it helps, some how.
Your welcome :)
Kito puts his spoon into a helping of fresh, hot, mashed potatoes as shown in the figure. Which process takes place when the two objects come together
A. The temperature of the spoon increases, but its thermal energy does not change
B. Energy in the form of heat is transferred from the warmer mashed potatoes to the cooler spoon
C. The thermal energy of both the mashed potatoes and the spoon increases as energy in the form of heat is transferred between them
(please answer quickly, I don't want to fail this test due to being stuck on this one)
Answer:
B. is the answer
Explanation:
Energy in form of heat is transferred from the warmer mashed potatoes to the cooler spoon.
How many grams of propane, C3H8, are needed to make 140 grams of water?
Answer:
85.6 g
Explanation:
Step 1: Write the balanced combustion equation
C₃H₈ + 5 O₂ ⇒ 3 CO₂ + 4 H₂O
Step 2: Calculate the moles corresponding to 140 g of H₂O
The molar mass of H₂O is 18.02 g/mol.
140 g × 1 mol/18.02 g = 7.77 mol
Step 3: Calculate the moles of C₃H₈ needed to produce 7.77 moles of H₂O
The molar ratio of C₃H₈ to H₂O is 1:4. The moles of C₃H₈ needed are 1/4 × 7.77 mol = 1.94 mol.
Step 4: Calculate the mass corresponding to 1.94 moles of C₃H₈
The molar mass of C₃H₈ is 44.10 g/mol.
1.94 mol × 44.10 g/mol = 85.6 g
Which element is malleable and ductile?
A. Phosphorus
B. Argon
C. Sodium
D. Chlorine
Can you help me answer all of these I’ll mark brainliest
Answer:
C.) Sodium
Explanation:
Sodium is an "Alkali Metal"
Kinetic energy is energy stored in an object due to its position.
True
Or
False
Answer:
[tex]\boxed {\boxed {\sf False}}[/tex]
Explanation:
Kinetic energy is the energy of movement or energy at work. An example is a ball rolling down a hill.
Potential energy is stored energy due to the position of an object. For example, a ball resting at the top of a hill.
The question incorrectly described potential energy as kinetic energy. Therefore, the answer is false.
How would you make up 75 ml of a 45 mg/ml BSA solution?
Answer: see below
Explanation: for 75 ml, take 45*75 mg of BSA and make up to 75 mL with distilled water.