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.
If the sun heated our atmosphere and the molecules began to s;read apart and rise but the atmosphere was to weak to keep them down , what would happen?
the law of states that mass cannot be created nor destroyed during a chemical reaction ?
a: conservation of mass
b: averages
c: conservation of momentum
d: conservation of energy
what is the average atomic mass of einsteinium? what are its common isotopes?
Answer:
Boom
Explanation:
The bomb is big and it goes boom and it also creates nuclear fragments everywhere
Calculate the mass of Aluminum Bromide that can be made with 5.6 moles of Aluminum
The mass of Aluminum tri bromide that can be made with 5.6 moles of Aluminum is 1,492.90 grams.
What is the relation between mass & moles?Relation between the mass and moles of any substance will be calculated by using the below equation as:
n = W/M, where
W = given massM = molar massGiven chemical reaction is:
2Al + 3Br₂ → 2AlBr₃
From the stoichiometry of the reaction, it is clear that:
2 moles of Al = produces 2 moles of AlBr₃5.6 moles of Al = produces 2 moles of AlBr₃Now mass of AlBr₃ will be calculated by using the above equation as:
W = (5.6mol)(266.59g/mol) = 1,492.90g
Hence required mass of AlBr₃ is 1,492.90g.
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What may be the most important tool to use for collecting data when conducting an investigation into how thermal energy affects metals? goggles beaker thermometer graduated cylinder
Answer:
thermometer
Explanation:
The most important tool to use when collecting data relating to how thermal energy affects metals would be the thermometer.
The thermometer is an instrument used to measure temperatures and the temperature of a body is a measure of the amount of thermal energy present in the body.
In order to obtain data relating to how thermal energy affects metals, the most important variable to take note of would be the thermal energy of the metals and this can only be done by the thermometer.
Which example describes a chemical change
taking place?
A. water turning into steam
B. sugar dissolving in warm water
C. alcohol evaporating from a food while baking
D. nails rusting while sitting outside
What's the balanced equation for Iron and copper (II) sulfate solution.
Answer:
2Fe + 3CuSO₄ → Fe₂(SO₄)₃ + 3Cu
Explanation:
The reactants are:
Iron = Fe
Copper (II) sulfate solution = CuSO₄
The reaction is given as:
Fe + CuSO₄ → Fe₂(SO₄)₃ + Cu
This is a single displacement reaction;
Now let us balance the equation;
aFe + bCuSO₄ → cFe₂(SO₄)₃ + dCu
Conserving Fe;
a = 2c
Conserving Cu;
b = d
Conserving S;
b = 3c
Conserving O;
4b = 12c
let b = 1;
c = [tex]\frac{1}{3}[/tex]
d = 1
a = [tex]\frac{2}{3}[/tex]
Multiply through by 3 to get whole numbers;
a = 2, b = 3, c = 1 and d = 3
2Fe + 3CuSO₄ → Fe₂(SO₄)₃ + 3Cu
Both the esophagus and the small intestine are involved in the digestion of food. The esophagus squeezes food into the stomach by wave-like muscle contractions. Peptidase enzymes in the small intestine break food molecules into smaller molecules.
Which statement best describes changes to food during digestion?
A. The muscle contractions result in physical changes, while the action of the peptidase results in chemical changes.
B. The muscle contractions result in chemical changes, while the peptidase results in physical changes.
C. The muscle contractions and the action of the peptidase both result only in physical changes.
D. The muscle contractions and the action in the peptidase both result only in chemical changes.
Answer:
The answer is: A
Explanation:
The wave-like contractions are to be considered a physical change as they do not take part in the breaking-down of the food. The peptidase is a chemical change because it is used to chemically break down the food to retrieve nutrients and such.
Identify and describe the steps in the technology design process.
Answer:
Steps of the technological design process include: identify a problem, research the problem, generate possible solutions, select the best solution, create a model, test the model, refine and retest the model as needed, and communicate the final solution.
Explanation:
hope it helps, please mark brainliest
Steps of the technology design process include: identify a problem, research the problem, generate possible solutions, select the best solution, create a model, test the model, refine and retest the model as needed, and communicate the final solution.
What is technology?Technology is the application of knowledge for achieving practical goals in a reproducible way.The word technology can also mean the products resulting from such efforts, including both tangible tools such as utensils or machines, and intangible ones such as software. Technology plays a critical role in science, engineering, and everyday life.
Technological advancements have led to significant changes in society. The earliest known technology is the stone tool, used during prehistoric times, followed by the control of fire, which contributed to the growth of the human brain and the development of language during the Ice Age. The invention of the wheel in the Bronze Age allowed greater travel and the creation of more complex machines. More recent technological inventions, including the printing press, telephone, and the Internet, have lowered barriers to communication and ushered in the knowledge economy.
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Which of the following students best describes an element?
Answer:
I dont see anything.
Explanation:
But an element is a substance that is made only out of one atom.
How many atoms are there in 1.225 moles of iron?
Show work
Answer:
1.2 × 10 to the power 25 . atoms of iron divide by a line 6.022× iron atoms per mole =~ 20 moles
Which product contains a strong base that would most likely completely dissolve in water?
drain cleaner
ammonia
baking soda
antacid
Answer:
Drain Cleaner
Explanation:
I just took the test and got it right :)
drain cleaner............................
Questlon 7 of 10
Which object will require the greatest amount of force to change its motion?
O A. A 72 kg object moving 25 m/s
O B. A 55 kg object moving 32 m/s
OC. A 75 kg object moving 22 m/s
O D. A 63 kg object moving 27 m/s
A 72 kg object moving 25 m/s will require the greatest amount of force
Further explanationGiven
mass of object and the velocity
Required
the greatest amount of force
Solution
Newton's 2nd law :
∑F = m. a
F = force, N
m = mass = kg
a = acceleration due to gravity, m / s²
Assuming the object is moving from rest (vo = 0) and the time needed to reach its velocity is the same (delta t = equal), it can be formulated:
[tex]\tt \Sum F=m.\dfrac{v_f-v_i}{\Delta t}\\\\F=m.\dfrac{v_f}{\Delta t}[/tex]
So the force on an object depends on the product of its mass and velocity
Or if we use the impulse and momentum formula
[tex]\tt F.\Delta t=m(v_f-v_i)\\\\F,\approx m.v_f[/tex]
So that we determine which is the greatest from the multiplication of mass and velocity will produce the greatest force as well
A 72 x 25 = 1800
B. 55 x 32 =1760
C. 75 x 22 = 1650
D.63 x 27 = 1701
Option A has the greatest force
One can find the pH of a substance by using ___.
A. a conductivity tester
B. a thermometer
C. plain paper indicator
D. litmus paper indicator
Explanation:
C. Plain paper indicator.
Litmus paper indcator can only tell you if the solution is acidic/neutral/alkaline, but not to what extent.
What is
the commission amount on 500000 at rate of 6%
Answer:
30000
Explanation:
6/100×500000 =30000
the density of a substance is 4.0g/cm3 if a sample of the substance has a volume of 25cm3 what is the mass
Answer:
100 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 = 4 × 25
We have the final answer as
100 gHope this helps you
23. Select the evidence that Thomson used to conclude his findings.
(a) Electrons become excited with more energy and then release that energy as atomic
spectra.
(b) Performed a series of experiments using pressure, properties of gases, and properties
of compounds.
(c) Battery Passed a cathode ray between positively and negatively charged plates and observed the cathode ray attracting to the positively charged plate.
(d) Bombarded a thin layer of gold foil with alpha particles and detected that some alpha
particles passed through the gold foil while others deflected.i
Answer:
The answer is C
Explanation:
Thomson conducted many tests with cathode rays. Which led to his discovery of the electron.
How many grams of carbon are required to produce 0.460 moles of SiC?
SiO2 + C → SiC + CO
Answer:
Sick Core corona +iep =Qurintine
Which list of terms best describes the formation of sedimentary rocks
Explanation:
Weathering - erosion - transportation - deposition
Sedimentary rocks are rocks that are formed from pre-existing rocks. The agents of denudation plays very important roles during the formation these rock types.
Existing rock bodies are broken down in to tiny fragments. These fragments are carried by erosion and transported. In the basin they are deposited as layers. Compaction, lithification and cementation occurs with burial. This will then lead to the formation of sedimentary rocks.Question 1
2 pts
The area around a charged object where the object can exert a force on
other charged objects is an electric
field
charge
induction
force
Answer:
A. electric field
Explanation:
took test
Answer:
electric field
Explanation:
How many moles are in 4.81x10^24 atoms of boron(B) ?
Show all of your work. Include units. round your answer to the correct number of significant figures.
Answer:
7.99 moles of boron
Explanation:
Given data:
Number of moles of B = ?
Number of atoms of B = 4.81 × 10²⁴ atom
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
4.81 × 10²⁴ atom × 1 mol / 6.022 × 10²³ atoms
0.799 × 10¹ mol
7.99 moles
The length of a year is equivalent to the time it takes for one.. (pls help I honestly forgot )
DOG SKELETAL SYSTEM BONES SKELETAL TISSUE BONE CELLS SMALLEST TO LARGEST
Answer:
tissue bone cells ,bones skeletal,dog skeletal system
Explanation:
Part A:
Identify a property of water that contributes its movement through the capillary tubes. Explain how the
molecular structure of water contributes to this property.
Plants use a similar mechanism to move water through their stems. In a specific species of plant, the
vessels are approximately 0.3 mm in diameter.
Part B:
Estimate how tall this species of plant can grow. Explain how the molecular structure of the vessels can
be modified to increase the maximum height of the plant without changing the diameter of the vessels.
Answer:
Part A
i) A property of water that contributes to its movement through capillary tubes is adhesion, which is the capacity of water to stick to other surfaces
ii) Water has a polar molecular structure as such the hydrogen present in the water molecules form bonds with the oxygen present in the silicon oxide molecules from which the capillary tube is normally made
Part B.
i) From the given graph, the function appears to have a vertical asymptote at x = 0, therefore, the plant can grow infinitely tall
ii) The molecular structure of the vessel can be modified such that the walls incorporate more oxygen molecules per mole which will increase the number and the strength of the hydrogen bond between the water molecules and the walls of the plant vessel and therefore, increase the capillary action, the water height and the maximum height of the tree
Explanation:
MARKING BRAINLIEST!
Many processes occur in the digestive system. Which process is best classified as a physical change?
A. digestive enzymes breaking down proteins into smaller fragments
B. teeth grinding an almond into smaller pieces in the mouth
C. bacteria converting lactose into simple sugars in the intestines
D. saliva converting the starch molecules in crackers into simpler sugars
Answer:
Teeth gridning
Explanation:
BC YOUR GRINDING IT
How might a collision between Neptune and Halley's Comet
affect Neptune's orbit?
Answer:
It will mess up the orbit around the sun
Explanation:
The impact of Halley's Comet with Neptune may force the asteroid to descend into Neptune's orbit, which may divert somewhat from its original path.
The collision of two heavenly bodies results in a powerful impact.
This collision might prevent Halley's Comet from continuing on its path and eventually colliding with Neptune.
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What is the difference between a molecular formula, structural formula and an electron dot formula? Give an example of each
Answer:
The molecular formula tell us what elements the atoms are, and how many moles and atoms are attributed toward each element. For example, molecular formula of glucose is . That means one molecule of glucose has 6 molecules of C, 12 molecules of hydrogen and 6 molecules of oxygen.
The structural formula of a chemical compound is a graphic representation of the molecular structure.
Electron dot diagram or a Lewis diagram or a Lewis structure.
Explanation:
A K+ ion is similar to a Cl– ion in that they both have the same A) nuclear charge B) number of electrons C) atomic number D) number of protons
Answer:
B) number of electrons
Explanation:
The two species:
K+ and Cl- have the same number of electrons.
A neutral atom of K has 19 electrons
A neutral atom of Cl has 17 electrons
Now,
To form K+, K will have to lose an electron and then the number of electrons becomes 18
To form Cl-, Cl will have to gain an electrons and then the number of electrons becomes 18
So, therefore, the number of electrons on both species is 18
How long does it take for 87.5 % of each isotope to decay?
(The isotopes are below)
Krypton-73= 27 seconds
Krypton-74= 11.5 minutes
Krypton-76= 14.8 hours
Krypton-81= 2.1 x 10^5 years
Answer:
Kr-73 = 23.625 sec
Kr-74 = 10.0625 minutes (603.75 seconds)
Kr-76 = 12.95 hours (777 minutes)
Kr-81 = 1.8375 * 10^6 years
Explanation:
What you do is multiply each of those amounts by 7/8.
27 * 7/8 = 189/8 = 23.625
23/2 * 7/8 = 161/16 = 10.0625
74/5 * 7/8 = 518/40 = 259/20 = 12.95
210000 * 7/8 = 1470000/8 = 183750 = 1.8375 * 10^6
what volume (in L) of a 3.95 M potassium chloride solution would be needed to make 325 mL of a 2.76 M solution by dilution
Explanation:
Moles of KCl in new solution = 0.325dm³ * (2.76mol/dm³) = 0.897mol.
Hence volume needed = 0.897mol / (3.95mol/dm³) = 0.227dm³ or 0.227L.