All good experiments should be...

Answers

Answer 1
Should have constant/controlled experiment. However all the other properties and factors should be in all groups or they should be controlled.

Related Questions

What can the chemical formula tell us about a compound?

Answers

Answer:

A chemical formula tells us the number of atoms of each element that is in a compound. It contains the symbols of the atoms for the elements present in the compound as well as how many there are for each element in the form of subscripts.

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what’s the most abundant isotope of lawrencium

Answers

Answer:

266Lr

Thirteen isotopes of lawrencium are currently known; the most stable is 266Lr with a half-life of 11 hours, but the shorter-lived 260Lr (half-life 2.7 minutes) is most commonly used in chemistry because it can be produced on a larger scale.

Explanation:

hopefully that helps you

What happens when the elements in group 2 react with water?

Answers

Answer:

The Group 2 metals become more reactive towards the water as you go down the Group.

Explanation:

These all react with cold water with increasing vigour to give the metal hydroxide and hydrogen. ... You get less precipitate as you go down the Group because more of the hydroxide dissolves in the water. Summary of the trend in reactivity.

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Which is an example of a current research focus in chemistry?

A. applying gene therapy to treat certain diseases

B. using hook-and-loop tape in the clothing industry

C. developing smoke detectors for common use

D. studying coal combustion as an energy source

Answers

d if i’m not mistaken

Answer:

b is the correct answer

do not trust answer one

Explanation:






Which number represetns a coefficient?
2
3
4
7

Answers

4 is the number that represents a coefficient

A sample of an unknown gas weighs 0.419 grams and produced 5.00L of gas at 1.00atm (unknown gas only) and 298.15K, what is the molar mass (g/mole) of this unknown gas

Answers

Answer:

molar mass of unknown gas = 1.987 g/mol

Explanation:

First, the number of moles of the unknown gas is found

Using the ideal gas equation: PV = nRT

P = 1.00 atm, V = 5.00 L, T = 298.15 K, R = 0.082 L.atm.mol⁻¹K⁻¹

n = PV/RT

n = (1.00 atm * 5.00 L)/(298.15 K *0.082 L.atm.mol⁻¹K⁻¹)

n = 0.2109 moles

Molar mass = mass/ number of moles

molar mass = 0.419 g/ 0.2109 mols

molar mass of unknown gas = 1.987 g/mol

The molar mass of unknown gas by using ideal gas equation = 1.987 g/mol.

Ideal gas equation

This equation gives the relation between pressure, volume, temperature as given below:

[tex]PV = nRT[/tex]

P = 1.00 atm, V = 5.00 L, T = 298.15 K, R = 0.082 L.atm.mol⁻¹K⁻¹

Substitute the above values in the above equation as follows:

n = (1.00 atm * 5.00 L)/(298.15 K *0.082 L.atm.mol⁻¹K⁻¹)

n = 0.2109 moles

Formula for molar mass

[tex]Molar mass = mass/ number of moles[/tex]

Calculate molar mass by using the above equation,

molar mass = 0.419 g/ 0.2109 moles

The molar mass of unknown gas = 1.987 g/mol

Find more information about ideal gas equation here,

brainly.com/question/4147359

Is air a homogeneous heterogeneous mixture or substance

Answers

Answer:

look at the explanation

Explanation:

The air that you breathe is a homogeneous mixture of oxygen, nitrogen, argon, and carbon dioxide, along with other elements in smaller amounts. Because each layer of the Earth's atmosphere has a different density, each layer of air is its own homogeneous mixture.

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What is the Kc equilibrium-constant expression for the following equilibrium? S8(s) + 24F2(g) 8SF6(g)

Answers

Answer:

[tex]Kc=\frac{[SF_6]^8}{[F_2]^2^4}[/tex]

Explanation:

Hello.

In this case, for the undergoing chemical reaction:

[tex]S_8(s) + 24F_2(g) \rightleftharpoons 8SF_6(g)[/tex]

We consider the law of mass action in order to write the equilibrium expression yet we do not include S8 as it is solid and make sure we power each gaseous species to its corresponding stoichiometric coeffient (24 for F2 and 8 for SF6), thus we obtain:

[tex]Kc=\frac{[SF_6]^8}{[F_2]^2^4}[/tex]

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A tree frog uses plants or trees for protection from the rain. The frog is protected from the rain and the tree is neither helped nor harmed

Answers

the Tree Frog hides from the rain and predators on plants or trees. The Tree Frog gets protection from the rain and predators and the tree or plant is neither harmed or helped in any way by the Tree Frog hiding on them.

Which of the following is an Elementary compound?

A. CO2

B. N2

C. SO2

D. H2S


heeeeeeeeeelp please please please ​

Answers

Answer:

Explanation:

In my opinion the answer should be SO2

Answer:

a should be answer i think.

help me please loves

Answers

Answer:

K and ba

Explanation:

Answer: K and Ba

Explanation:

When 435 J of heat is added to 3.4 g of olive oil that's at 21 Deg C, it's
temperature increases to 85 Deg C. Calculate the specific heat of Olive oil? Show work

Answers

Answer:

k Nishant

Explanation:

i don't know sorry but u can search in google

The pOH of an aqueous solution of 0.480 M trimethylamine (a weak base with the formula (CH3)3N) is .

Answers

Answer:

Explanation:

Kb of  (CH₃)₃N is 7.4 x 10⁻⁵

initial concentration of (CH₃)₃N   a   is .48 M

(CH₃)₃N    +   H₂O =  (CH₃)₃NH⁺  +  OH⁻

a - x                                     x               x  

x² / (a - x )  = Kb

x is far less than a so a - x can be replaced by a .

x² / a   = Kb

x²  = a x Kb = .48 x 7.4 x 10⁻⁵ = 3.55 x 10⁻⁵ = 35.5 x 10⁻⁶

x = 5.96 x 10⁻³

pOH = - log ( 5.96 x 10⁻³ )

= 3 - log 5.96

= 3 - .775

= 2.225

Which of these is the best definition of biotechnology??

A) The study of chemical processes in living things

B) the use and application of living things and science

C) the application of engineering principles to solve medical problems

D) the study of forces

Answers

C most likely sorry if I’m wrong
I believe the answer is B) the use and application of living things and science.

Bio means life and technology is scientific knowledge for different purposes.

Sorry if this is wrong

True or False: Particles that are moving faster have a higher temperature

Answers

Answer:

true

Explanation:

I'm not sure why cause I dont know how to explain but it's TRUE

Answer:

True  

Explanation:

The particles moving faster in a substance the hotter it gets.

Which of the following is a good definition of matter?
O A. Anything that is made up of light and gravity
O B. Anything that has mass and takes up space
O C. Anything that produces heat and mass
O D. Anything that has energy and creates heat

Answers

Answer:

B

Explanation:

I did the question before and got it right.

Answer :
B

Explanation:
I got it right on my test.

calculate the mass of N2 gas which has a volume 0.227 at STP​

Answers

Hi I just wanted you know I have to work at the gym I will call when you I have a good night love I will

What types of materials are better at absorbing energy from radiation?

Answers

Answer:

Explanation:

Materials are clothes and heavy rope

In which atmospheric layer is the ozone layer?
A.troposphere
B.mesosphere
C.stratosphere
D.thermosphere

Answers

Answer:

stratosphere

Explanation:

contains a high concentration of ozone in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.

Answer:

stratosphere

Explanation: Most atmospheric ozone is concentrated in a layer in the stratosphere, about 9 to 18 miles (15 to 30 km) above the Earth's surface. Ozone is a molecule that contains three oxygen atoms.

How to separate given mixture?

Answers

Answer:

Chromatography involves solvent separation on a solid medium.

Distillation takes advantage of differences in boiling points.

Evaporation removes a liquid from a solution to leave a solid material.

Filtration separates solids of different sizes.

Explanation:

A chemist decomposes samples of several compounds; the masses of their constituent elements are listed. Calculate the empirical formula for each compound.

a. 1.245 g Ni, 5.381 g I,
b. 2.677 g Ba, 3.115 g Br,
c. 2.128 g Be, 7.557 g S, 15.107 g

Answers

Answer:

you can see the empirical formula at the pic

The empirical formula for compound (a) is NiI2, (b) is BaBr2 and (c) is BeS.

What is empirical formula?

Empirical formula of a compound is defined as the simplest whole number ratio of atoms present in a compound.

(a) 1.245 g Ni : 5.381 g I

Mole of Ni ; Mole of I = 1.245/59 : 5.381/127 = 0.02 : 0.04 = 1:2

So the formula is NiI2

(b) 2.677 g Ba : 3.115 g Br

Mole of Ba : Mole of Br = 2.677/137 : 3.115/60 = 0.019 : 0.038

= 0.02 : 0.04 = 1:2

So the formula is BaBr2

(c) 2.128 g Be : 7.557 g S

Mole of Be : Mole of S = 2.128/9 : 7.557/32 = 0.2 : 0.2 = 1:1

So the formula is BeS

Thus, empirical formula for compound (a) is NiI2, (b) is BaBr2 and (c) is BeS.

To learn more about empirical formula, refer to the link below:

https://brainly.com/question/11588623

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Scientists are experimenting with pure samples of isotope X which is radioactive. The sample has a mass of 20. Grams. The half-life was measured to be 232 seconds. There is a second sample that weighs 80 grams. What is the half-life of the second sample

Answers

Answer:

Explanation:

Half life of radioactive materials do not depend upon the mass of the material . It only depends upon the nature of radioactive materials . The half life of 20 g is 232 seconds . That means 20 gram will be reduced to 10 gram in 232 seconds .

Half life of 80 gram is also 232 seconds . So , 80 gram will be reduced to 40 gram in 232 second .

for the following reaction, provide the missing information

Answers

Answer:

19. Option B. ⁰₋₁B

20. Option D. ²¹⁰₈₄Po

Explanation:

19. ²²⁸₈₈Ra —> ²²⁸₈₉Ac + ʸₓZ

Thus, we can determine ʸₓZ as follow:

228 = 228 + y

Collect like terms

228 – 228 = y

y = 0

88 = 89 + x

Collect like terms

88 – 89 = x

x = –1

Thus,

ʸ ₓZ => ⁰₋₁Z => ⁰₋₁B

²²⁸₈₈Ra —> ²²⁸₈₉Ac + ʸₓZ

²²⁸₈₈Ra —> ²²⁸₈₉Ac + ⁰₋₁B

20. ᵘᵥX —> ²⁰⁶₈₂Pb + ⁴₂He

Thus, we can determine ᵘᵥX as follow:

u = 206 + 4

u = 210

v = 82 + 2

v = 84

Thus,

ᵘᵥX => ²¹⁰₈₄X => ²¹⁰₈₄Po

ᵘᵥX —> ²⁰⁶₈₂Pb + ⁴₂He

²¹⁰₈₄Po —> ²⁰⁶₈₂Pb + ⁴₂He

PLSSS HELP Match each image to the
correct step of meiosis. PLS HELP

Answers

prophase 1 is the second image of the first column, metaphase 1 is the second image of the second column, anaphase 1 is the first image of the second column, prophase 2 is the third image of the second column, metaphase 2 is the first image of the first column and telophase 2 is the third image of the first column

Answer:

Explanation:

Here you go!! Hope this helps.

A sample of propane, C3H8, contains 13.8 moles of carbon atoms. How many total moles of atoms does the sample contain

Answers

Answer:

[tex]Total = 50.6\ moles[/tex]

Explanation:

Given

[tex]Propane = C_3H_8[/tex]

Represent Carbon with C and Hydrogen with H

[tex]C = 13.8[/tex]

Required

Determine the total moles

First, we need to represent propane as a ratio

[tex]C_3H_8[/tex] implies

[tex]C:H = 3:8[/tex]

So, we're to first solve for H when [tex]C = 13.8[/tex]

Substitute 13.8 for C

[tex]13.8 : H = 3 : 8[/tex]

Convert to fraction

[tex]\frac{13.8}{H} = \frac{3}{8}[/tex]

Cross Multiply

[tex]3 * H = 13.8 * 8[/tex]

[tex]3 H = 110.4[/tex]

Solve for H

[tex]H = 110.4/3[/tex]

[tex]H = 36.8[/tex]

So, when

[tex]C = 13.8[/tex]

[tex]H = 36.8[/tex]

[tex]Total = C + H[/tex]

[tex]Total = 13.8 + 36.8[/tex]

[tex]Total = 50.6\ moles[/tex]

If 25.6 mL isopropyl alcohol fully decomposes, what mass of H2 is formed? The density of isopropyl alcohol is 0.785 g/mL. g

Answers

Answer:

The correct answer is 0.67 g H₂

Explanation:

Isopropyl alcohol (C₃H₇OH) can decompose to give acetone (C₂H₆OH) and hydrogen gas (H₂) according to the following chemical equation:

C₃H₇OH (g) ⇒ C₂H₆CO(g) + H₂(g)

We can calculate the initial mass of isopropyl alcohol from the density and volume data:

density = m/V = 0.785 g/mL

⇒ m = density x V = 0.785 g/mL x 25.6 mL = 20.096 g C₃H₇OH

According to the chemical equation 1 mol of C₃H₇OH gives 1 mol H₂. The molar mass of C₃H₇OH is:

molar mass C₃H₇OH = (12 g/mol x 3) + (1 g/mol x 7) + 16 g/mol + 1 g/mol = 60 g/mol

molar mass H₂ = 1 g/mol x 2 = 2 g/mol

So, we obtain: 2 g H₂ from 60 g C₃H₇OH. We multiply this stoichiometric ratio (2 g H₂/60 g C₃H₇OH) by the initial mass of C₃H₇OH to obtain the mass of H₂ is formed:

20.096 g C₃H₇OH x (2 g H₂/60 g C₃H₇OH) = 0.6698 g ≅ 0.67 g H₂

Question 11
4 pts
Using the formula 2H202 --> 2H2O + O2, if 7.30 moles of peroxide are
decomposed, how many moles of oxygen will be formed?

Answers

Answer:

3.65 mol O₂

Explanation:

Step 1: RxN

2H₂O₂ → 2H₂O + O₂

Step 2: Define

Given - 7.30 mol H₂O₂

Solve - x mol O₂

Step 3: Stoichiometry

[tex]7.30 \hspace{3} mol \hspace{3} H_2O_2(\frac{1 \hspace{3} mol \hspace{3} O_2}{2 \hspace{3} mol \hspace{3} H_2O_2} )[/tex] = 3.65 mol O₂

When does carbon dioxide absorb the most heat energy?
during freezing
during deposition
during sublimation
during condensation

Answers

During sublimation

This has been posted on here before so you could’ve searched it lol.

Best of luck :))

Answer:

during sublimation

Explanation:

just took the test

How do the test variables (independent variables) and outcome variables (dependent variables) in an experiment compare? A. The test variables (independent variables) and outcome variables (dependent variables) are the same things. B. The test variable (independent variable) controls the outcome variable (dependent variable). C. The test variable (independent variable) and outcome variable (dependent variable) have no affect on each other. D. The outcome variable (dependent variable) controls the test variable (independent variable).

Answers

Answer:

I'm on the exact same queston

Answer:

The test variable (independent variable) controls the outcome variable (dependent variable)

Explanation:

its right on study island

The empirical formula of CBr2 has a molar mass of 515.46 g/mol. What is the molecular formula of this
compound

Answers

Answer:

C3Br6

Explanation:

C= (1 X 12.011) = 12.011

Br= (2 X 79.904)= 159.808

159.808+12.011 = 171.819

515.46 divided by 171.819 = 3.00

so you mulitpy CBr2 by 3 which gives you C3Br6

Other Questions
please help me answer this TIMED TEST HURRY WILL NAME BRAINLEIST Min is asked to balance the equation below.Original: Ca3P2 + H2O Ca(OH)2 + PH3Mins result: Ca3P2 + H2O Ca3(OH)2 + PH3Which best describes Mins method for balancing the chemical equation?It is correct, because now there are three Ca atoms on each side of the equation.It is incorrect, because the identity of the original product has changed.It is correct, because Ca3(OH)2 creates a more stable compound.It is incorrect, because the subscript 2 should be added instead If 25.6 mL isopropyl alcohol fully decomposes, what mass of H2 is formed? The density of isopropyl alcohol is 0.785 g/mL. g Read the claim below.The government should not use taxpayers' money to fund the arts.Select the piece of evidence that best supports this claim.The largest government arts program costs the average taxpayer only aboutforty-five cents per year.Private citizens, corporations, and foundations already spend billions of dollarseach year to support the arts.The Federal Art Project was a government-funded program that employedthousands of artists during the Great Depression. Sita said to Renu you have failed in your mission San Francisco's response to the 1906 Fire compare to the policy of Chinese Exclusion? A runner sprinted for 117 yards (yd). How many feet (ft) is this? First fill in the blank on the left side of the equation using one of the ratios. Then write your answer on the right side of the equation. ft mi yd 1760 yd 1 mi 3 ft 1 ft 12 in 1 yd Ratios: 1 mi 1760 yd 1 yd 3 ft 12 in 1 ft . in 117 yd 1 ft 0 x IK IT LOOKS CONFUSING SO LOOK AT THE PICTURE HELP ME PLEASE!!!!:) What is the slope of the line that passes through the points (-5,7) and (10, 1)?m = 5/2Bm = -5/2m = -2/5Dm = 2/5 What area was claimed by two colonial regions? what 5-2 to the power of 5 HELP PLEASE BRAINLESS ANSWER GETS 20 POINTSAn albatross is a large bird that can fly 400 kilometers in 8 hours at a constant speed. Using d for distance in kilometers and t for number of hours, anequation that represents this situation is d-50t.Enter the smaller of the two constants of proportionality. James is studying different kinds of weather.Rain has water drops that are larger than 0.02 inch in diameter.Small hailstones are less than 14 inch in diameter.Complete the statement that best represents the different kinds of weather James studied. Select one correct answer from each box to complete the sentence. ABCDEFGH Antonio's dad bought gas for their family's ATV two weeks in a row. Last week, he bought 12 gallons for $35.40. This week, he bought 9 gallons for $25.83. How much more did Antonio's dad pay per gallon last week? reeeeeeeeeeeeeeeeeeeeev can you tell me the answer Jill is building a wooden raised bed garden for her vegetable she wants the frame to have dimension X feet by X +3 feet if she wants the garden to have a maximum area of 50 ft. what are the possible values of X Please help ASAP!!! Will give brainlist! The empirical formula of CBr2 has a molar mass of 515.46 g/mol. What is the molecular formula of this compound Who is the Father of Texas? Which of the following is a good example of visual encoding?