Answer:
C
Explanation:
A. analyzing results
B. collecting data
C. choosing controlled variables
D. making a prediction
The correct answer would be choosing controlled variables.
The controlled variables are factors that are kept constant among the different groups of subjects during the course of an experiment so as to be able to isolate the effects of a single factor - the independent variable.
There are basically 3 types of variables in a scientific experiment;
1. The independent variable
2. The dependent variable
3. The controlled variable
The independent variables are the variables whose effects are to be determined in the course of experiments. The dependent variables are the variables that are actually measured during the course of experiments and whose values vary along with that of the independent variables. The controlled variables are other variables required for the experiment but which must be kept constant among subjects in order to be able to isolate the effects of the independent variable.
The correct option is C.
Please select the word from the list that best fits the definition left standing after the collapse of a sea arch
Answer:
Sea Stack
Explanation: :)
Answer:
A
Explanation:
Which one is the right answer?
Answer:
a) p waves travel slower then 5 waves
When a pendulum swings, at which point is kinetic
energy highest:
Answer:
3
Explanation:
Commercial scuba divers use tanks filled with a mixture of gases known as Trimix on very long, deep dives. Trimix is composed of 70% nitrogen, 10% oxygen and 20% helium. The total pressure of the Trimix inside a certain tank at the beginning of the dive is 118.4 atm. A. What is the partial pressure of the oxygen in the tank?
Answer:
Partial pressure of O = 11.84 atm
Explanation:
To solve the excersise we think in the partial pressure law with mole fraction.
Mole fraction of gas = Partial pressure of gas / Total pressure
We have data of all the mole fractions:
0.70 N0.10 O0.20 HLet's find out the partial pressure of oxygen in the tank. We replace data in the formula:
0.10 = Partial pressure of gas / 118.4 atm
0.10 . 118.4 atm = Partial pressure of gas → 11.84 atm
If we determine all the partial pressures:
0.70 . 118.4 atm = 82.88 atm → Partial pressure N
0.20 . 118.4 atm = 23.68 atm → Partial pressure He
We can determine the partial pressure of the trimix.
Sum of partial pressures of each gas = Total pressure of the mix
11.84 atm + 82.88 atm + 23.68 atm = 118.4 atm
(A way to see, if our operations were ok)
The partial pressure of oxygen in the tank is required.
The partial pressure of the oxygen in the tank is 11.84 atm.
[tex]x_o[/tex] = The mole fraction of oxygen = 10%
[tex]p[/tex] = The total partial pressure in the tank = 118.4 atm
The mole fraction of a gas is equal to the ratio of partial pressure of the gas to the total partial pressure.
[tex]x_o=\dfrac{p_o}{p}\\\Rightarrow p_o=x_op\\\Rightarrow p_o=0.1\times 118.4\\\Rightarrow p_o=11.84\ \text{atm}[/tex]
The partial pressure of the oxygen in the tank is 11.84 atm.
Learn more:
https://brainly.com/question/14281129?referrer=searchResults
How many neutrons are present in an atom of
2×21=how many are there
A compound is different from a mixture because a compound
Answer:
Compound: A substance that is made up of more than one type of atom bonded together.
Mixture: A combination of two or more elements or compounds which have not reacted to bond together; each part in the mixture retains its own properties.
Explanation:
The different substances in a mixture are not chemically combined, whereas the different elements in a compound are. The atoms do not combine in the mixture, but they combine when they form a compound.
3. True or False: White light is a mixture of all colors of the visible
spectrum.
O True
False
it's true ....
plz mark my answer as brainlist plzzzz vote me also
What is the equilibrium constant of a reaction?
A. It is the ratio of the concentrations of products to the concentrations of reactants.
B. It is the ratio of the number of moles of products to the number of moles of reactants. C. It is the concentrations of products multiplied by the concentrations of reactants.
D. It is the number of moles of reactants subtracted from the number of moles of products.
Answer:
A. It is the ratio of the concentrations of products to the concentrations of reactants.
Explanation:
The equilibrium constant of a chemical reaction is the ratio of the concentration of products to the concentration of reactants.
This equilibrium constant can be expressed in many different formats.
For any system, the molar concentration of all the species on the right side are related to the molar concentrations of those on the left side by the equilibrium constant. The equilibrium constant is a constant at a given temperature and it is temperature dependent. The derivation of the equilibrium constant is based on the law of mass action. It states that "the rate of a chemical reaction is proportional to the product of the concentration of the reacting substances. "Answer: A
Explanation:
a p e x
help me pleaseeee, ty if you doo:))
Answer:
9 is the correct answer
How does one determine how much of a molecule is produced in a reaction?
O A. Oxidation states are used to calculate the number of product molecules.
B. The molar masses of the molecules tell how many grams of product will form.
O c. The coefficients and molar masses are used to calculate amounts of molecules
D. The mass of the products is determined by adding the mass of the reactants.
Answer:
c
Explanation:
i doubt it
The coefficients and molar masses are used to calculate the amounts of molecules. Hence, option C is correct.
What is a molecule?The smallest particle of a substance has physical and chemical properties of that substance. Molecules are made up of one or more atoms.
A molecule can be determined by how much is produced in a reaction through the coefficients and molar masses are used to calculate the amounts of molecules.
Hence, option C is correct.
Learn more about molecules here:
https://brainly.com/question/14130817
#SPJ5
Write True/False against the following statements and also correct the false statement.
Greater the calorific value better is the fuel.
Answer:
I think it is true you should go for true
What variable represents specific heat in the equation Q = mCAT?
O A. The variable c
O B. The variable T
C. The variable m
O D. The variable Q
Answer:
the variable A represented specific heat capacity
Answer: The Variable T
Explanation:
How does the atomic radius of an element is related to its metallic character
Answer:
The large the atomic radius the more the metallic character of elements
Explanation:
The atomic radius is related to the metallic character in a way that the larger the atomic radius, the more metallic a body becomes.
Therefore, as we go down a group, metallic character increases.
Metallic character relies on the ability and willingness of an atom to share its valence electrons. As the size of an atom becomes large, the more metallic it is and the more its metallic character. In some other cases this character is known as electropositivity.why is newtons first law of motion important to science plsss help :(
Explanation:
every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force
Answer: Newton's 1st law of motion explains how things move and how forces work on their movement, which makes it an extremely important discovery.
Explanation: If we were to place an object into space, we could observe how it behaves without any external influences.
please help me i willgive brain list
Answer:
the molecular formulas of:Butane is C4H10butene is C4H8Butyne is C4H6.Hexane is C6H14Hexene is C6H12Hexyne is C6H10hope it helps........Which of the following is NOT an example of potential energy?
A. car moving down the highway
B. log on a fire
C. person standing on a diving board
D. liter of gasoline
Answer:
A. car moving down the highway
Explanation:
Potential energy is when the energy is being held in, as in, it is very still, and not moving.
When a car is moving down a highway, it is releasing kinetic energy, instead of potential.
How many Cl atoms are in Zn(ClO3)2?
O A. 2
O B. 1
O c. 3
O D. 6
There are two chlorine band six oxygen atoms in Zn ( ClO₃ )₂ molecule. Therefore, option A is correct.
What is chlorine atom ?With an atomic mass of 35.45 and an atomic number of 17, chlorine has an average of 17 protons, 17 electrons, and 18 neutrons in each of its atoms. Chlorine, which belongs to the halogen family on the Periodic Table, reacts vigorously with metals to produce salts.
Numerous industrial applications exist for chlorine as well. Including the production of plastics like PVC, solvents like tetrachloromethane, chloroform, and dichloromethane, as well as bulk goods like bleached paper products. In addition, it is utilized in the production of paints, textile colors, antiseptics, and pharmaceuticals.
Chlorine is a negative ion because it has a charge of 1, 1 more than protons. Atoms acquire or lose electrons during the formation of ions until their outer energy level is reached.
Thus, option A is correct.
To learn more about chlorine atom, follow the link;
https://brainly.com/question/1127028
#SPJ5
What is the percent composition by mass for sodium (Na) in sodium phosphate (Na3PO4)? % Na = (______/______)x100% = _______% NNA
The percent composition by mass for sodium (Na) in Sodium phosphate (Na₃PO₄) : 42.07%
Further explanationGiven
Compound of Sodium phosphate (Na₃PO₄)
Required
The percent composition by mass for sodium (Na)
Solution
The Comparative Law (Proust ) : compounds are formed from elements with the same Mass Comparison
MW Na₃PO₄ = 163,94 g/mol
Ar Na=22,989769g/mol
[tex]\tt \%mass~Na=\dfrac{3.Ar~Na}{MW~Na_3PO_4}\times 100\%\\\\\%mass~Na=\dfrac{3\times 22.99}{163.94}\times 100\%\\\\\%mass~Na=42.07\%~Na[/tex]
Help pls!!! Thnk you
Answer:
521 nm
Explanation:
From the question given above, the following data were obtained:
Frequency (v) = 5.76×10¹⁴ s¯¹.
Wavelength (λ) =.?
RECALL: velocity (c) of light = 3×10⁸ m/s
Thus, we can obtain the wavelength of the green light by using the following formula:
c = vλ
3×10⁸ = 5.76×10¹⁴ × λ
Divide both side by 5.76×10¹⁴
λ = 3×10⁸ / 5.76×10¹⁴
λ = 5.21×10¯⁷ m
Next, we shall convert 5.21×10¯⁷ m to nanometer (nm). This can be obtained as follow:
1 m = 1×10⁹ nm
Therefore,
5.21×10¯⁷ m = 5.21×10¯⁷ m × 1×10⁹ nm / 1 m
5.21×10¯⁷ m = 521 nm
Thus, 5.21×10¯⁷ m is equivalent to 521 nm
Therefore, the wavelength (λ) of the photon of the green light is 521 nm.
Answer:
the wavelength (λ) of the photon of the green light is 521 nm.
When a substance is changed from a solid to liquid energy is_ _ _ _ d *81 points*
Answer:
That change is known as melting.
Explanation:
I am not sure what you are asking. I hope this helps!
help me please... tyy if you do :))
Answer:
a) HCl
Explanation:
As we know, that HCl or Hydrogen Chloride is a diatomic compound. It is formed due to the Chemical reaction of Hydrogen and Chlorine. As both Hydrogen and Chlorine have valencies of 1, the Net Valency of the Compound HCl is 1 itself. This separates it from the rest of the compounds. The rest of the compounds need to have more than 2 atoms of each kind and have different valencies too.
What is the correct order of the scientists in order of their work related to the structure of an atom from earliest to most recent?
Neils Bohr, Ernest Rutherford, JJ Thomson, John Dalton, Democritus and Erwin Schrodinger
Erwin Schrodinger, JJ Thomson, John Dalton, Neils Bohr, Ernest Rutherford and Democritus
Democritus, John Dalton, JJ Thomson, Ernest Rutherford, Neils Bohr and Erwin Schrodinger
John Dalton, Neils Bohr, JJ Thomson, Democritus, and Ernest Rutherford and Erwin Schrodinger
PLEASE HELP !!!
Answer:
C. democritusm John dalton, JJ Thomason, Ernest Rutherford, Neils Bohr, and Erwin Schrodinger.
The correct order of the scientists in order of their work related to the
structure of an atom from earliest to most recent include Democritus, John
Dalton, JJ Thomson, Ernest Rutherford, Neils Bohr, and Erwin Schrodinger.
Democritus was regarded as one of the earliest scientist who first proposed
atomic theory around 460 BC which was then modified and used by others
such as John Dalton, JJ Thomson, Ernest Rutherford and Neils Bohr.
The most recent of them all was Erwin Schrodinger which was the wave
equation for electron movements in the 20th century.
Read more on https://brainly.com/question/20339664
The reaction energy type that has a negative value at the end of the reaction is called: a Barothermic b Exothermic c Endothermic d Isothermic
Answer:
b) Exothermic
Explanation:
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
I need answers
Question 2 (2 points)
Which of the following is an example of BALANCED forces?
A ball rolling uphill
O A ball sitting motionless on the ground
O A ball bouncing on the ground
O A ball rolling downhill
Answer:
Concepts: Physical Forces
In order for an object to be balanced, then it must be in equilibrium which means that no additional forces are being exerted. A ball sitting motionless would result in a balanced force that exerts no additional forces.when 3.18 g of copper (||) oxide were carefully heated in a stream of dry hydrogen, 2.54 g of copper and 0.72 g of water were formed determine the number of moles of hydrogen atoms which combine with one mole of oxygen atoms
Answer:
the number of moles of atom is 0.91584
Describe two ways the material in illustrates the importance of creativity in scientific investigations
Answer:
J.J Thompson make use of creativity to explain cathode ray tube experiment.
Also, creativity was used by Daltons to explain Joseph Proust's work.
Explanation:
This problem is all about the the beginning part of chemistry that is the atomic theory. The atomic theory was starts from the time of people like Democritus and down to people like J.J Thompson and John Dalton. Although it has been registered and credited that Dalton is the father of atomic theory many people has also worked on it before him for instance person like Joseph Proust. The reason behind this because some works that has been done by other people such as Democritus[who was the first person to start atomic studies] does not have any scientific evidence.
Creativity is needed when it concerns scientific research and investigation. This is what scientists such as John Daltons and J.J Thompson have used. J.J Thompson make use of creativity to explain cathode ray tube experiment. Also, creativity was used by Daltons to explain Joseph Proust's work.
The temperature of 15 grams of water is increased by 3.0 Celsius degrees. How much heat was absorbed by the water? (specific heat of water: 4.18 J/g deg C)
Answer:
188.1J
Explanation:
obtained from Q=MCT
Help me answer this plz.
Answer:
87.58 L of C₂H₂
Explanation:
We'll begin by calculating the number of mole in 250 g of CaC₂.
This can be obtained as follow:
Mass of CaC₂ = 250 g
Molar mass of CaC₂ = 40 + (12×2)
= 40 + 24
= 64 g/mol
Mole of CaC₂ =?
Mole = mass /Molar mass
Mole of CaC₂ = 250 / 64
Mole of CaC₂ = 3.91 moles
Next, the balanced equation for the reaction. This is given below:
CaC₂ + 2H₂O —> C₂H₂ + Ca(OH)₂
From the balanced equation above,
1 mole of CaC₂ reacted to produce 1 mole of C₂H₂.
Next, we shall determine the number of mole of C₂H₂ produced by the reaction of 250 g (i.e 3.91 moles) of CaC₂. This can be obtained as follow:
From the balanced equation above,
1 mole of CaC₂ reacted to produce 1 mole of C₂H₂.
Therefore, 3.91 moles of CaC₂ will also react to produce 3.91 moles of C₂H₂.
Finally, we shall determine the volume of C₂H₂ produced from the reaction. This can be obtained as follow:
Recall:
1 mole of any gas occupy 22.4 L at STP.
1 mole of C₂H₂ occupied 22.4 L at STP.
Therefore, 3.91 moles of C₂H₂ will occupy = 3.91 × 22.4 = 87.58 L
Thus, 87.58 L of C₂H₂ is produced from the reaction.
What is the mass of an object that has a density of 2,86 g/mL and a volume of
75 mL
Answer:
214.5 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
From the question we have
mass = 75 × 2.86
We have the final answer as
214.5 gHope this helps you
