when would a scientist choose to conduct a controlled experiment​

Answers

Answer 1

Answer:a scientist would choose to conduct a controlled experiment when it has all the necessary precautions and has the equipment to do so

Explanation:thank you

Plz mark for brainlist


Related Questions

Which pair of elements form an ionic bond with
each other?
A. KCL
B. ICL
C. PCL
D. HCL

I think it’s A and D but if it’s not both can you please explain why it’s one and not the other?

Answers

Answer:

Yes Both A) KCL and D) HCL are correct...

Answer:

It's only A

Explanation:

Potassium (K) is a metal and Chlorine (Cl) is a nonmetal, and ionic compounds are formed between metals and nonmetals. So KCl forms ionic bonds.

Hydrogen (H) and Chlorine (Cl) are both nonmetals, and only covalent bonds form between nonmetals. (Only exception is when its an acid, then it's ionic)

Also, the question indicated which "pair" and not "pairs" meaning that there is only one answer, and I'm more likely to go with A rather than D.

What is the mass of an aluminum block if the density of aluminum is 2.70
g/cm and the volume of that block is 4.8 cm?

Answers

Answer: 50 M

Explanation:

Mass

Density×Volume2.7(4.8)11.6111.6g

Formula used

Density=Mass/Volume

Why does the Hubble Space Telescope take clearer pictures than other telescopes?

Answers

Answer:

Space-based telescopes like Hubble get a much clearer view of the universe than most of their ground-based counterparts. ... Ground-based telescopes can't do the same, because the Earth's atmosphere absorbs a lot of the infrared and ultraviolet light that passes through it.

Diazene, N2H2 (also known as diimine), is commonly used as a reagent for organic syntheses. Label each image with the type of
bond in diazene that it shows.

Answers

The first image shown at the left hand side is a pi bond. The other two images show sigma bonds.

In chemistry, a bond results from the overlap of atomic orbitals. This overlap may be end to end (sigma bond) or side by side (pi bond). Having said this, it is easier to decide whether the bonds in the image shown are sigma or bi bonds.

If we label the images; 1,2,3 from left to right, we can see that the overlap in image 1 is side by side. The electron density lies above and below the plane of the bond. This is a pi bond. In images 2 and 3, the overlap occurs in an end to end manner. This is a sigma bond.

Learn more: https://brainly.com/question/14018074

50 PTS!!!!!
What type of chemical reaction is Aerobic Cellular Respiration?

Answers

Answer: During aerobic respiration, catabolic reactions convert larger complex organic molecules into ATP, the chemical that drives most physiological processes in the body.

Explanation:

If 2.5 moles of PA react completely, how many
moles of P203 are formed?

Answers

Answer:

For every 2 moles of Na used, 2 moles of NaCl are produced.

Explanation:

calculate the mass percentage of each element in aluminum oxide.Then calculate themass of aluminum in a 3.62 gram sample of of aluminum

Answers

1. The mass percentage of each element in aluminum oxide Al₂O are:

i. The mass percent of Al in Al₂O₃ is 52.9%

ii. The mass percent of O in Al₂O₃ is 47.1%

2. The mass of Al in 3.62 g of Al₂O₃ is 1.73 g

1i. Determination of the percentage of Al

Molar mass of Al₂O₃ = (2×27) + (3×16) = 102 g/mol Mass of Al of Al₂O₃ = 2 × 27 = 54 gPercentage of Al =?

Percentage = mass / mass of sample × 100

Percentage of Al = (54 / 102) × 100

Percentage of Al = 52.9%

1ii. Determination of the percentage of O

Molar mass of Al₂O₃ = 102 g/mol Mass of O of Al₂O₃ = 3 × 16 = 48 gPercentage of O =?

Percentage = mass / mass of sample × 100

Percentage of O = (48 / 102) × 100

Percentage of O = 47.1%

2. Determination of the mass of Al in 3.62 g of Al₂O₃.

102 g of Al₂O₃ contains 54 g of Al.

Therefore,

3.62 g of Al₂O₃ will contain = (3.62 × 54) / 102 = 1.73 g of Al.

Thus, 1.73 g of Al is present in 3.62 g of Al₂O₃.

Learn more about percentage composition: https://brainly.com/question/3940233

Polyvalent ions are

1) Anions with variable charges
2) Cations from columns 3 to 12
3) Ions that can be positive or negative

Answers

Answer:
3) Ions that can be positive or negative

Hope this helps!

I NEED HELP WItH THIS 5th GRADE QUESTION ITS VERY VERY EASY no Links PLZ and I will Report any useless AWnser PLZ HELP WILL mARK AS BRAINLIST AND Will giVE 1000 Points if correct Answer
How is the mass of a solid measured?

By estimating
With a beaker
With a ruler
With a scale

Answers

Answer:

A Beaker or graduated cylinder

Explanation:

Place the solid into the graduated cylinder. Measure the amount of water in the graduated cylinder. The product is the solid's mass wich i mean by that is what number the water level is at.

Answer:

Beaker

Explanation:

Would you expect a Boron (B) atom with atomic mass = 9.999 to be stable?

Answers

The balance of forces allows to find the result for the question if the isotope of boron 9.99 una  is stable:

The boron isotope of mass 9.99 uma is unstable because the repulsive force increases.

The stability of atomic nuclei depends on the balance the force is electrostatic repulsion between the protons and the strong interaction of attraction.

One way to achieve this balance is to increase the separation of the protons with uncharged particles between them, the neutral ones, the strong interaction is of the same magnitude for protons and neutrons, therefore the repulsion is decreased and the strong attraction interaction is maintained. .

In the case of Boron, which has 5 protons, the stable structures have more atomistic 10 and 11 una, which is why it has 5 and 6 neutrons each. Therefore each proton has  a neutrons next to it and in the other case a proton at the end has two neutrons, this causes the distance between the protons to increase, decreasing the electrostatic repulsion.

It indicates that we have a Boron nucleus of mass 9.999. The number of protons must remain fixed, therefore there are only 4 neutrons.

Consequently, some of the protons does not have a neutron next to it and can approach the other proton, therefore the electrostatic repulsion increases and the stability of the atom decreases.

In conclusion, using the balance of Forces we can find the result for the question if the isotope of boron 9.99 una is stable:

The boron isotope of mass 9.99 amu is unstable because the repulsive force increases.

Learn more about nuclear stability here: https://brainly.com/question/897383

Which of the following is not part of an amino acid?
A. ammonium group
B. carboxylate group
C. ether group
D. unique "R" group

Answers

Answer:

C

Explanation:

Ether group does not exist in amino acids

Ammonium group is on one side

the carboxylate group is opposite to the ammonium group

the R group defines what amino acid it is.

Define Endothermic reaction in terms of Deta H

Answers

I didn't learn about that topic in school,but I found this :

I hope it helps<3

Describe echolocation. Give an example of an animal that uses echolocation.

Answers

dolphin and whales use echolocation

what is the chemistry of super glue

Answers

cyanoacrylate

When cyanoacrylate polymerizes, the cyanoacrylate sticks together on an atomic level, and it becomes solid. Super Glue solidifies in all the microscopic crevices of an object that it moved into when it was a liquid, and it can form chemical bonds with any anions in the object.

need help with question please ..
-20 points

Answers

Answer:

B oklolol

[tex][tex]\purple{\rule{45pt}{7pt}}\purple{\rule{45pt}{999999pt}}[tex][/tex]

Can someone help? Thank you.

Answers

that' the answer i don't need an explanation

C= ( F - 32) / 1.8
86 F = ?

Answers

Answer:

C = 30

Explanation:

C = (86 - 32)/1.8

C = (54)/1.8

C = 30

1. List the ketose carbon(s) that is(are) reduced with NaBH4.

Answers

Answer:

ehh im nit sure but here!

Explanation:

What is black powder made of? (Please provide percentage composition of elements as well) Will give brainliest

Answers

Answer:

Black powder has 3 main ingredients: Sulfur ([tex]S[/tex]), charcoal ([tex]C_{7}H_{4}O[/tex]), and potassium nitrate ([tex]KNO_{3}[/tex]).

Charcoal is basically just burnt wood and potassium nitrate can easily be displaced.

Keep in mind that this is BLACK POWDER and not actual gunpowder. The difference between the both is significant since gunpowder has a lot more refining processes it has to go through to be actually used in firearms and such.

The percentage composition of black powder should be 75% Potassium Nitrate, 10% Sulfur, and 15% charcoal.

Should be noted that black powder is not a safe compound to deal with, as static friction could ignite it.

There are other alternatives to Black powder such as nitroglycerin (used in dynamites) which is way more powerful and useful in doing mines and exploration but is an extremely tricky and reactive substance to work with.

I do hope this is just for educational purposes because you need to be certified to even just experiment with this (and there are laws to synthesize such as well, which I won't take any responsibility for)

Answer:

sulfur, charcoal and potassium nitrate

Explanation:

Payback

An aqueous solution was prepared by dissolving 266.07 g of AgNO3 ( 169.88 g/mol) in enough water to make a total volume of 250.0 ml. What is the molarity of the solution

Answers

Answer:

The correct answer is 6.265 M.

Explanation:

To find the molarity of the solution, we first must recall that molarity represents the number of moles of solute divided by the number of liters of solution. Thus, our first step should be to convert the solute amount in grams to moles, using the given molar mass.

266.07 g * (1 mol/169.88 g) = 1.5662 mol

Now, we can find the molarity using the following formula:

Molarity = moles solute/liters solution

M = 1.5662 mol/0.25 L

M = 6.265 M

Therefore, the molarity of the solution is 6.265 M.

Hope this helps!

patient requires blood transfusion. what is the next thing to do? discuss​

Answers

You have to find the blood type so you don’t cross contaminate

When the radiation isn't quite strong
enough to kill right away a terrible
Condition follows what is it called
and what is happening.

Answers

When radiation isn’t Enough to kill you but it’s too much for your body to handle you would get what is called radiation poisoning. the symptoms are vomiting, nausea, diarrhea, headache, and several others

Sulfuric acid reacts with sodium carbonate to form water, a salt, and a gas. Write the formulas for the salt and other compound that are formed in the reaction.

Answers

Answer:

H2So4 + Na2Co3 -> H20 + Na2So4 + CO2

The chemical formulas for the salt and other compound that are formed in the reaction are Na₂SO₄,H₂O and CO₂.

What is chemical formula?

Chemical  formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols  of elements. It also makes use of brackets and subscripts.

Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form  is called empirical formula.

It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.

There are four types of chemical formula:

1)empirical formula

2) structural formula

3)condensed formula

4)molecular formula

Learn more about chemical formula,here:

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Which of the following best represents a ​chemical change?

A. Chopping wood
B. Silver tarnishing (changing color)
C. Grape kool-aid mix dissolving in water
D. Dry ice turning into a gas (sublimation- a change of state)

Answers

B. silver tarnishing

how do you Calculate the molarity of 250 ml of solution in which 2.7 g of MgCl2 are dissolved

Answers

Answer:

Molar mass of MgCl2 is 95 g/mol

Mg = 24 g/mol and Cl = 35.5 ×2 = 71 g/mol

moles = mass given/ molar mass

= 2.7/95 = 0.028 mol

volume = 250/1000 = 0.25 dm3 (ml is the same as dm3)

molarity of MgCl2 = moles/volume

= 0.028/0.25

= 0.112 mol/dm3

which planet is closests to the moon

Answers

Answer:

Earth

Explanation:

Answer:

Earth

Explanation:

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It takes 120 mL of 0.15 M of carbonic acid (H2CO3) to neutralize 300 mL of sodium hydroxide (NaOH) for the following balanced chemical reaction:

2NaOH + H2CO3 → N2CO3 + 2NaOH

The concentration of the sodium hydroxide _____.

Answers

First of all, you need to convert mL to L; 120mL = 0.12L, 300mL = 0.3L.

n (moles of carbonic acid) = C (concentration) x V (volume)
n = 0.15M (0.15 mol L-1) x 0.12L
n = 0.018 mol

C (conc. of NaOH) = 0.018 mol x 2 moles (because there’s 2x NaOH) = 0.036 mol
C = n / V
C = 0.036 mol / 0.3 L
C = 0.12 mol L-1

As an electron in an atom moves from a higher energy state to a lower energy state, the atom
A
becomes a negative ion
В.
becomes a positive ion
С.
releases energy
D.
absorbs energy

Answers

Answer:B

Explanation:

What is the total pressure exerted by a mixture containing two gases if the partial pressure of one gas is 70 kPa and the partial pressure of the other gas is 30 kPa?

Answers

Answer:

The total pressure of a mixture of gases can be defined as the sum of the pressures of each individual gas: Ptotal=P1+P2+… +Pn. + P n . The partial pressure of an individual gas is equal to the total pressure multiplied by the mole fraction of that gas.

Explanation:

hope this helps have a wonderfull day!

To calculate the atomic mass of an element, the percent
abundance of etch isotope is needed. ?

Answers

Answer:

List the known and unknown quantities and plan the problem. Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass

Explanation:

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