Please answer! If you answer you get brainlist :D

Please Answer! If You Answer You Get Brainlist :D

Answers

Answer 1

Answer:

A test variable is a user-defined, name-value pair that stores and refers to information throughout a test and between tests. For example, in a study looking at how tutoring impacts test scores, the dependent variable would be the participants' test scores, since that is what is being measured...

The control group is defined as the group in an experiment or study that does not receive treatment by the researchers and is then used as a benchmark to measure how the other tested subjects do. For example, The control group is used in an experiment as a way to ensure that your experiment actually works. Your experimental group would be given the Gatorade and your control group would be given regular water. The conditions must be exactly the same for all members of the experiment.

A limiting factor is anything that constrains a population's size and slows or stops it from growing. Some examples of limiting factors are biotic, like food, mates, and competition with other organisms for resources. Limiting factors are usually expressed as a lack of a particular resource.

Infectious agents commonly spread through the direct transfer of bacteria, viruses, or other germs from one person to another. This can happen when an individual with the bacterium or virus touches, kisses, or coughs or sneezes on someone who isn't infected.

Explanation:


Related Questions

A gas-forming reaction produces 1.95 m3 of gas against a constant pressure of 196.0 kPa. Calculate the work done by the gas in joules.

Answers

Answer:

Work done W = -382,206 J (Approx)

Explanation:

We know that;

1 atm = 101.32 kPa

1 L-atm = 101.325 J

1 m³ = 1,000 L

Computation:

Work done W = -P∆V

Pressure = 196 kPa × (1 / 101.32 kPa)

Pressure = 1.9344 atm

∆V = 1.95 × (1000 L) = 1,950 L

So,

W = -(1.9344 atm) × (1,950 L)

W = -3772.0 L-atm

Work done W = -3772.0 L-atm × (101.325 J / 1 L.atm)

Work done W = -382,206 J (Approx)

The work done by the gas in Joules is equal to 3,763.5‬ Joules.

Given the following data:

Pressure = 196.0 kPa. Volume = 1.95 [tex]m^3[/tex]

Conversion:

1 atm = 101.325

X atm = 196.0 kPa

X = [tex]\frac{196.0}{101.325} = 1.93\; atm[/tex]

Conversion:

1 [tex]m^3[/tex] = 1000 Liter

1.95 [tex]m^3[/tex] = 1950 Liter

To calculate the work done by the gas in Joules:

Mathematically, the work energy by a system is given by the formula:

[tex]Work = P \delta V[/tex]

Where:

P is the pressure. V is the volume.

Substituting the parameters into the formula, we have

[tex]Work\;energy = 1.93 \times 1950[/tex]

Work energy = 3,763.5‬ Joules.

Read more: https://brainly.com/question/22599382

Question 2 (2 points)
Saved
How many grams of water do will you need to prepare 480 g of 8.5% solution of
C6H12O6

Answers

Answer:

[tex]m_w=439.2g[/tex]

Explanation:

Hello!

In this case, since the by-mass percent of a solution is a measure of the mass of the solute over the mass of the solution:

[tex]\%m/m=\frac{m_{solute}}{m_{solution}} *100\%[/tex]

As we know the mass of the solution and the by-mass percent, we can compute the mass of glucose in the 480 g of solution:

[tex]m_{solute}=\frac{\%m/m*m_{solution}}{100\%}[/tex]

Thus, by plugging in the data, we obtain:

[tex]m_{solute}=\frac{8.5\%*480g}{100\%}=40.8g[/tex]

Finally, since the solution is made up of glucose and water, we compute the mass of water as follows:

[tex]m_w=m_{sol}-m_{solute}=480g-40.8g\\\\m_w=439.2g[/tex]

Best regards!

which of the following is an example of a decomposition reaction

Answers

Answer:

Examples of decomposition reactions include the breakdown of hydrogen peroxide to water and oxygen, and the breakdown of water to hydrogen and oxygen.

A party balloon filled with helium deflates to 2/3 of its original volume in 8.0 hours. How long will it take an identical balloon filled with the same number of moles of air (ℳ = 28.2 g/mol) to deflate to 1/2 of its original volume?

Answers

Answer:

The easy way to do this is to assume the number of moles. Make it a number easily divided by both 2 and 3, so say 6. Now you can have numbers to plug in to Graham's Law to find the second rate, then use the second rate to find the time. Does that make sense?


What is the wavelength, in nanometers, of light with a frequency of 1.90x10^15 Hz?

Answers

Answer:

1.58×10² nm

Explanation:

Given data:

Frequency of light = 1.90 ×10¹⁵ Hz

wavelength of light = ?

Solution:

Speed of light = wavelength  × Frequency

Speed of light = 3×10⁸ m/s

3×10⁸ m/s  = λ × 1.90 ×10¹⁵ Hz

 Hz = s⁻¹

λ =  3×10⁸ m/s / 1.90 ×10¹⁵s⁻¹

λ = 1.58×10⁻⁷ m

meter to nm:

1.58×10⁻⁷ m ×10⁹ nm/ 1m

1.58×10² nm

what type of change occurs when rust on a nail a. chemical change b. physical change

Answers

Answer:

Chemical change

Explanation:

The rusting of iron/a nail is a chemical change

Iron (Fe) and Oxygen (O) combine to create the compound Iron Oxide (Fe2O3), which is rust.

How many alkyl substituents does N-ethyl-N-methylaniline have?
one
two
O three
o eight
none

Answers

Answer:

Two.

Explanation:

Hello!

In this case, considering the attached picture wherein you can see the presence of the parent chain as aniline, we can see radicals at the nitrogen, named by N-ethyl and N-methyl which are the present alkyl substituents. In such a way, the benzene ring is not considered an alkyl radical because it belongs to the parent chain on aniline and therefore, N-ethyl-N-methylaniline has two alkyl substituents.

Best regards!

There are two alkyl substituents attached to the nitrogen; one ethyl and one methyl group

Aniline consists of a benzene ring to which an -NH2 moiety is attached. Usually, it is possible for the any of the two hydrogen atoms in the -NH2 moiety to become substituted leading to N-alkylated product.

In the compound N-ethyl-N-methylaniline, there are two alkyl substituents attached to the nitrogen; one ethyl and one methyl group as shown in the image attached to this answer.

Learn more:  https://brainly.com/question/6284546

A pure substance made of two two or more elements that are chemically combined is a(n)

Answers

Answer:

A pure substance made up of two or more elements that are chemically combined is a compound

Explanation:

How many moles of mercury are 4.000 x 1022 atoms of mercury?

Answers

Answer:

0.06642 moles of mercury

Explanation:

Step 1: Given data

Moles of mercury: 4.000 × 10²² atoms

Step 2: Calculate the number of moles of mercury that correspond to 4.000 × 10²² atoms of mercury

To convert atoms to moles, we need to consider the Avogadro's number: there are 6.022 × 10²³ atoms of mercury per mole of mercury.

4.000 × 10²² atoms × (1 mol/6.022 × 10²³ atoms) = 0.06642 mol

HELP!!!!!!
I DON'T KNOW THE ORDER!!

Answers

Answer:

for 1 solid its freezing.

for 2 solid and liquid its melting

for 6 liquid to gas its evaporation and for 5 gas  to liquid its condensation.

Explanation:

hope this helped :)

Answer:

solid->liquid= melting

liquid->solid= freezing

gas->liquid= consendation

liquid->gas= evaporation

Calculate the standard cell potential, ∘cell, for the equation Co(s)+F2(g)⟶Co2+(aq)+2F−(aq) Use the table of standard reduction potentials. ∘cell=

Answers

Answer:

3.15 V

Explanation:

Step 1: Write the balanced cell reaction

Co(s) + F₂(g) ⟶ Co²⁺(aq) + 2 F⁻(aq)

Step 2: Identify both half-reactions:

Cathode (reduction): F₂(g) + 2 e⁻ ⟶ 2 F⁻(aq)    E°red = 2.87 V

Anode (oxidation): Co(s) ⟶ Co²⁺(aq) + 2 e⁻      E°red = -0.28 V

Step 2: Calculate the standard cell potential

We will use the following expression.

E°cell = E°red,cathode - E°red,anode

E°cell = 2.87 V - (-0.28 V) = 3.15 V

Given E°cell > 0, the reaction is spontaneous.

Taking into account the definition of standard cell potential, E°cell has a value of 3.15 V.

The balanced cell reaction is:

Co(s) + F₂(g) ⟶ Co²⁺(aq) + 2 F⁻(aq)

First of all, it must be taken into account that oxidation is a reaction where an atom, ion or molecule loses electrons while reduction corresponds to the gain of electrons from an atom, ion or molecule.

Both oxidation and reduction depend on the change in the oxidation state of the atom, that is, on the difference in the charge of the atom in a reaction.

The oxidation and reduction reactions always occur simultaneously for what are generally known as oxidation-reduction reactions or redox reactions.

So, the anode corresponds to the negative electrode which normally oxidizes in the electrolytic chemical reaction while the cathode corresponds to the positive electrode which normally reduces its oxidation state when it receives electrons.

Si, in this case, the both half-reactions will be:

Cathode (reduction): F₂(g) + 2 e⁻ ⟶ 2 F⁻(aq)    E°red = 2.87 V Anode (oxidation): Co(s) ⟶ Co²⁺(aq) + 2 e⁻      E°red = -0.28 V

The potential of an Ecel cell is a measure of the difference in electronic energy between the two electrodes. The electronic energy of each electrode is related to the force with which the reaction occurs at the electrode-solution interface. The unit in which it is measured is the volt.

In electrochemistry, because a cell reaction is made up of two half-cell reactions, each of which has a characteristic electrode potential, the potentials measure the driving force of the two half-reactions.

The cell potential is obtained by subtracting the potentials of both half cells as shown below:

E°cell= Ecatode - Eanode

So, in this case, the Ecell is calculated as:

E°cell = 2.87 V - (-0.28 V) = 3.15 V

In summary, E°cell has a value of 3.15 V.

Learn more:

https://brainly.com/question/14011488?referrer=searchResultshttps://brainly.com/question/13892163?referrer=searchResultshttps://brainly.com/question/17186824?referrer=searchResultshttps://brainly.com/question/13000465?referrer=searchResultshttps://brainly.com/question/12990827?referrer=searchResults

Each pure substance has characteristic physical and chemical properties that can be used to identify it.

Compare and contrast physical properties and chemical properties of a substance. Give and example for each:

Answers

Stuff like color, and density are examples of physical properties. Flammability and corrosion/oxidation are examples of chemical properties

Give two everyday examples of the thermal energy of a substance being decreased

Answers

Answer:

An example of the thermal energy of a substance being decreased is with our food. With the thermal energy of food being decreased it is easier for foods to be eaten comfortably without any damage to the tongue or alimentary canal.

Another good example is in the handling of hot objects in the home. Thermal energy decrease in objects such as iron, pots etc helps to prevent serious burns and injuries.

Answer:

Water turning into ice

juice frozen to make popsicles

Explanation:

When something goes from liquid to a solid, that is a process called freezing. When a object loses thermal energy the particles move slower forming a solid.

The polar bear runs at a speed of 8.3 m/sec, how long will it take it to run 200
meters?

Answers

Answer:speed of 6.5 meters per second, what is the distance she covers in that time? ... backstrokes at an average speed of 8 meters per second, how long will it take ... 200m smis. 255. 7. Lauren's SUV was detected exceeding the posted speed limit ... Suppose the polar bear was running on land instead of swimming. ... V = 8.3mls.

Explanation:

[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]

Actually Welcome to the Concept of the Kinematics.

Since, we know that,

Time = Distance / Speed

so here, Speed = 8.3 m/s and Distance= 200m

so we get as, T = 200/8.3 => 24.09 seconds.

Hence, time taken will be => 24.09 seconds.

2. Calculate the new molanty of a solution formed when 20 ml of water is added to 100 ml of
0.2M NaOH​

Answers

Answer:

New molarity = M₂ = 0.167 M

Explanation:

Given data:

New molarity = M₂ = ?

Final volume = V₂ = 100mL + 20 mL = 120 mL

Initial volume =M₁ =  100 mL

Initial molarity =V₁ = 0.2 M

Solution:

M₁V₁       =    M₂V₂

0.2 M × 100 mL = M₂ × 100 mL

M₂ = 0.2 M × 100 mL/120 mL

M₂ = 20 M.mL/120 mL

M₂ = 0.167 M

A chemist dissolves 249.mg of pure perchloric acid in enough water to make up 380.mL of solution. Calculate the pH of the solution. Be sure your answer has the correct number of significant digits.

Answers

Answer:

pH = 2.18

Explanation:

Perchloric acid (HClO₄) is a strong acid. This means that in an aqueous solution it completely dissociates into H⁺ and ClO₄⁻ species.

First we convert 249 mg HClO₄ into moles, using its molecular weight:

249 mg HClO₄ ÷ 100.46 mg/mmol = 2.49 mmol HClO₄

Because it is a strong acid, 2.49 mmol HClO₄ = 2.49 mmol H⁺

We calculate the molar concentration of H⁺:

2.49 mmol H⁺ / 380 mL = 6.52x10⁻³ M

Finally we calculate the pH of the solution:

pH = -log[H⁺] = -log(6.52x10⁻³)pH = 2.18

A.) What is the mass in g of 5 mols of Mg?
B.) If you are given 7.4 *10^23 atoms of Cu, how many mols of Cu do you have?

Answers

Answer:

Mass of Mg  = 120 g

1.23 moles of Cu

Explanation:

A)

Given data:

Number of moles of Mg = 5 mol

Mass of Mg = ?

Solution:

Number of moles = mass/molar mass

Molar mass of magnesium is 24 g/mol.

5 mol = mass/ 24 g/mol

Mass = 5 mol × 24 g/mol

Mass = 120 g

B) Given data:

Number of atoms of Cu = 7.4 ×10²³ atom

Number of moles of Cu = ?

Solution:

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

7.4 ×10²³ atom × 1 mol / 6.022 × 10²³ atom

1.23 moles of Cu

2 C2H2 + 5 O2
2 H2O + 4 CO2
what reaction type

Answers

Answer:

Combustion reaction

General Formulas and Concepts:

Chemistry

Synthesis Reactions: A + B → ABDecomposition Reactions: AB → A + BSingle-Replacement Reactions: A + BC → AB + CDouble-Replacement Reactions: AB + CD → AD + BC

Explanation:

Step 1: Define

2C₂H₂ + 5O₂ → 2H₂O + 4CO₂

Step 2: Identify

Any organic molecule reacting with oxygen to produce water and carbon dioxide is a combustion reaction.

We also see from the RxN that is is a double replacement reaction.

Answer:

Answer: 0.4 g

Explanation:

1) Balanced chemical equation:

2) 2C2H2 + 5 O2 → 4CO2 + 2 H2O

3) mole ratios:

2 mol C2h2 : 5 mol O2

4) Convert 0.13 g C2H2 into number of moles

n = mass in grams / molar mass

molar mass C2H2 = 2 *12g/mol + 2*1 g/mol = 26 g/mol

n = 0.13 g / 26 g/mol = 0.005 mol

5) Set the proportion with the unknown

5 mol O2             x

----------------- = ---------------

2 mol C2H2      0.005 mol C2H2

x = 0.005 mol C2H2 * 5 mol O2 / 2 mol C2H2 = 0.0125 mol O2

6) Convert 0.0125 mol O2 to grams

mass = number of moles * molar mass

molar mass of O2 = 32 g/mol

mass = 0.0125 mol * 32 g/mol = 0.4 g

Answer: 0.4 g

Explanation:

An atom has 10 protons and 10 electrons. What happens to the charge if you add 1 more electron

Answers

Answer:

it becomes a negstive charge

A student with a body temperature of 37℃ holds a piece of ice that has a temperature of -8℃. Which statement best explains what happens?

A. Heat transfers coldness from the ice to the student's hand.
B. Thermal energy transfers heat from the student's hand to the ice.
C. Heat transfers thermal energy from the student's hand to the ice.
D. Thermal energy transfers coldness from the student's hand to the ice.

Answers

Answer: C. Heat transfers thermal energy from the student's hand to the ice.

Explanation:  It seems confusing; b and c seem to be saying the same thing, but the definition of heat is the transfer of thermal energy from a warmer object to a colder object.

A substance that functions to prevent rapid, drastic changes in the pH of a body fluid by changing strong acids and bases into weak acids and bases is called a(n):

A. Buffer
B. Salt
C. Enzymes
D. Coenzyme

Answers

I believe the answer is A) Buffer
A. Buffer is the answer.

How many atoms are in 15.6 grams of silicon?

Answers

Answer:

3.34 x 1023 atoms

Explanation:

When NaCl is dissolved in water, it separates into Na+ and CI-ions, which are also dissolved in water. How would the phase of the NaCl, the Na+, and the CI-
be written in the reaction equation?
A. (g)
B. (1)
C. (aq)
D.(s)​

Answers

Answer:

C aq

Explanation:

Means desolves in water

When NaCl is dissolved in water, it separates into its constituent ions Na+ and Cl- ions. The phase of the ions are written as (aq) and that of NaCl is written as (s) .

What is NaCl ?

Sodium chloride is an ionic compound formed by the transfer of electrons from the metal sodium to the nonmetal chlorine. It is used as the common table salt.

Na contains  one valence electron and Cl contains 7 valence electrons. Hence, Na can donate that electron to Cl to achieve octet in both. When Na loss an electron it forms Na+ and Cl gains the electron to form Cl-. These two ions are then attracts to form the NaCl.

When NaCl is dissolved in water the bond between these two ions weaken and the ions gets released  into the solution. The ions in the solution is indicated with the phase aqueous (aq) and the undissolved NaCl is in solid (s) state.

Find more on NaCl:

https://brainly.com/question/18248731

#SPJ7

Which unit is used to express a amount of thermal energy

Answers

Answer:

Joule

Explanation:

Answer:

The calorie

Explanation: as the amount of thermal energy necessary to raise the temperature of one gram

Which of the following statements is true about covalent bonds?
a) The shared electrons provide both atoms with an octet.
b) Sometimes electrons are gained to provide an atom with an octet.
OC) Hydrogen will share its one electron to obtain an octet
O d) The shared electrons are attracted by the nuclei of both atoms.
e) both a and d.

Answers

Answer:

the answer is D.)

Explanation:

What is the molarity of 9.0 moles of NaCl dissolved in 15.0 liters if solution?

Answers

Molarity= moles/Volume => 9/15 = 0.6 mol/L

Why is K lighter than Na

Answers

Answer:

Basically, in the case of sodium and potassium the increase in shell size outweighs the pull of the core on the outer shell electron and so potassium is less dense than sodium. When we more from Na to K, effect of increase in volume is more pronounced as compared to effect of increase in atomic mass.

To prepare 380 mL of 0.500 M NaCl (MW = 58.5 g/mol), how many grams of sodium chloride is required?

Answers

This answer did not come from me but here you go!
44 g NaCl
Explanation:
The problem provides you with the molarity and volume of the target solution, so your first step here will be to use this information to figure out how many moles of sodium chloride,
NaCl
, it must contain.
Once you know that, use the compound's molar mass to convert the number of moles to grams.
So, molarity is defined as the number of moles of solute per liter of solution. In your case, a
0.77 M
solution will contain
0.77
moles of sodium chloride, your solute, in
1.0 L
of solution.
Your target solution has a volume of
985
mL

1 L
10
3
mL
=
0.985 L
which means that it will contain
0.985
L solution

= 0.77 M

0.77 moles NaCl
1
L solution
=
0.75845 moles NaCl
Sodium chloride has a molar mass of
58.44 g mol

1
, which basically means that one mole of sodium chloride has a mass of
58.44 g
.
In your case,
0.75845
moles of sodium chloride will have a mass of
0.75845
moles NaCl

58.44 g
1
mole NaCl
=




¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
a
a
44 g
a
a

11.12 grams of sodium chloride is required to prepare 380 mL of 0.500 M NaCl (MW = 58.5 g/mol).

HOW TO CALCULATE MASS:

The mass of a substance can be calculated by multiplying the number of moles of the substance by its molar mass.

However, the number of moles of sodium chloride must first be calculated by multiplying the molarity by its volume.

Molarity = no. of moles ÷ volume

0.500M = n ÷ 0.380L

n = 0.5 × 0.380

n = 0.19mol

mass of NaCl = 58.5g/mol × 0.19mol

Mass of NaCl = 11.12g

Therefore, 11.12 grams of sodium chloride is required to prepare 380 mL of 0.500 M NaCl (MW = 58.5 g/mol).

Learn more about how to calculate mass at: https://brainly.com/question/14948089?referrer=searchResults

If the % acetic acid listed on a vinegar bottle is 4%, what is the implied uncertainty of the acetic acid concentration

Answers

Answer:

This question appears incomplete

Explanation:

This question appears incomplete because the data provided only makes it possible to calculate the certainty of the acetic acid content per total volume of the vinegar. Thus, the 4% means for every 100 mL of the vinegar, there is 4 mL of acetic acid present. To calculate the volume of acetic acid in any other volume of vinegar, the formula will be

volume of acetic acid = 4/100 × total volume of vinegar

A negative ion is known as a(n) *
ionic radius.
valence electron.
cation.
anion.

Answers

Answer:

Positively charged ions are called cations; negatively charged ions, anions

Other Questions
Tanisha rode her bike 19.625 miles in 2.5 hours. What was her average speed Determine the function type. If it is a polynomial, state the degree of the polynomial and whether it is an even degree polynomial or an odd degree polynomial.f(x)=[tex]\sqrt{x}[/tex]-3 what does this quote mean? Do you agree with it? Why or why not? express as a trinomial(2x-3)(3x-3) The image shows a water feature. Which term describes feature A? spring geyser water table artesian well If the price for a meal is $15 and there is a $3 dollar tip, what percentage of the total is the tip? The African continent is home to the world's longest river and longest freshwater lake.Please select the best answer from the choices provided.TF Prompt: Write a paragraph that states and defends a claim about which object from A History of the World in100 Objects is the most historically significant. Choose one of the following objects: the Benin plaques, TheGreat Wave, the Sudanese slit drum, or the suffragette-defaced penny. True of False: You can reduce impulse buying by doing research before each purchase. Drag the tiles to the correct boxes to complete the pairs. Not all tiles will be used.Match the coordinates with the points on the coordinate plane.PQRST(-4.5, -3)arrowRight(3.5, 0)arrowRight(-2, 4)arrowRight(4, 6.5)arrowRight If scientists wanted to date the oldest rocks on Earth's surface, why wouldn'tthey use rocks formed at the Mid-Ocean ridges ? For what type of study does the United States Census Bureau assist scientists by completing research?A) DemographicB) FertilityC) OceanographicD) Environmental Please help this is for math.... 975 divide by 39 equals what Graph -2x + y = 8 please help How many stanzas appear in emily dickinsons my friend must be a bird? My friend must be a bird. Because it flies! Mortal my friend must be. Because it dies! Barbs has it like a bee. Ah curious friend. Thou puzzlest me! A) five B) two C) one D) seven what was the french royal academy dedicated to teaching Enter the value of p so that the expression 3(4+n) is equivalent to 3(n+p) PLEASE HELP ME!!!!!!!!!!!!!!!!!!!! 4. . My father's son is my-5. My step-mother's son is my step-brotherbrother-in-law