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2 years ago

7

Nicolaas constructed a working model of the hydrologic cycle during science class. He used an open flame, liquid water, two larg

e glass bulbs, and some glass tubing.Which of the following processes does Nicolaas' model demonstrate?

2 answers:

kumpel [21]2 years ago

7 0

Answer: heat energy and gravity

Explanation:

Nastasia [14]2 years ago

3 0

Surface, condensation, evaporation, precipitation

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What elements of paint can help forensic scientists compare samples to each other?

saul85 [17]

It would have to be paints consists of pigments,solvents, and binders. Once the [paint has been applied and has dried, the pigments are still able to determine the matched samples.

4 0

2 years ago

Describe a single measurement that you could make that shows that a kettle is less than 100% efficient (providing evidence that

alexgriva [62]

Answer:

As you haven't explained what measurements you took before solving this problem, I will explain the general procedure to evaluate the efficiency of a kettle. I hope it helps you. I´ll send an attachement file with the full answer, since I couldn't write it here.

I assume that the material that is going to be heated in the kettle is water.

1- You have to boil water in it and take the time it takes to its boiling point (in seconds).

2- You have to evaluate the amount of energy the water absorbed Q with the efficiency formula which I explain in the attachement file.

3- Divide Q by the time it took to bring the water to boiling so you can have the power it consumed.

4- You divide the last value you obtained by the Kettles's power rating.

5- Multiply the last value by 100 to obtain a percentage value of efficiency.

Explanation:

Efficiency is the ration of a machine's useful work, in this case how much energy the water absorbed to get to its boiling point divided by the time it took to get to this point, and the total energy expended, in this case the kettles's power rating.

7 0

2 years ago

What mass of powdered drink mix is needed to make a 0.5 M solution of 100 mL?

Maru [420]

Answer:

There is 17,114825 g of powdered drink mix needed

Explanation:

<u>Step 1 :</u> Calculate moles

As given, the concentration of the drink is 0.5 M, this means 0.5 mol / L

Since the volume is 100mL, we have to convert the concentration,

⇒0.5 / 1 = x /0.1 ⇒ 0.5* 0.1 = x = 0.05 M

This means there is 0.05 mol per 100mL

e

<u>Step 2 </u>: calculate mass of the powdered drink

here we use the formula n (mole) = m(mass) / M (Molar mass)

⇒ since powdered drink mix is usually made of sucrose (C12H22O11) and has a molar mass of 342.2965 g/mol.

0.05 mol = mass / 342.2965 g/mol

To find the mass, we isolate it ⇒0.05 mol * 342.2965 g/mol = 17,114825g

There is 17,114825 g of powdered drink mix needed

3 0

2 years ago

Read 2 more answers

The terms motif (fold) and domain describe levels of protein organization more complicated than primary or secondary structure.

posledela

Answer:

Each specific property of motif and domain is explained.

Explanation:

Domain;

May retain a 3D structure when separated from rest of the protein.
Unit of tertiary structure because alpha helix and beta sheets are units of secondary structure.
Stable globular units like pyruvate kinase
May be distinct functional units in a protein

Motif;

Repetetive supersecondary structure because they contain cluster of secondary structure.
Beta Alpha Beta unit is an example of motif
Clusters of secondary structure

Both Motif and Domain;

Stabilized by hydrophobic interactions like hydrogen bonding stabilize the both.
Depends on primary structure like the arrangement of amino acid in polypeptide chain determine the secondary and tertiary structure of proteins.

8 0

2 years ago

When 1.00 g of boron is burned in o2(g) to form b2o3(s), enough heat is generated to raise the temperature of 733 g of water fro

Bas_tet [7]

<span>Answer: For this problem, you would need to know the specific heat of water, that is, the amount of energy required to raise the temperature of 1 g of water by 1 degree C. The formula is q = c X m X delta T, where q is the specific heat of water, m is the mass and delta T is the change in temperature. If we look up the specific heat of water, we find it is 4.184 J/(g X degree C). The temperature of the water went up 20 degrees. 4.184 x 713 x 20.0 = 59700 J to 3 significant digits, or 59.7 kJ. Now, that is the energy to form B2O3 from 1 gram of boron. If we want kJ/mole, we need to do a little more work. To find the number of moles of Boron contained in 1 gram, we need to know the gram atomic mass of Boron, which is 10.811. Dividing 1 gram of boron by 10.811 gives us .0925 moles of boron. Since it takes 2 moles of boron to make 1 mole B2O3, we would divide the number of moles of boron by two to get the number of moles of B2O3. .0925/2 = .0462 moles...so you would divide the energy in KJ by the number of moles to get KJ/mole. 59.7/.0462 = 1290 KJ/mole.</span>

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2 years ago