can someone help me please

Answer:

oxygen reacts with iron to form rust

Explanation:

The given options are;

(1)Oxygen has a melting point of 55 K.

(2) Oxygen can combine with a metal to produce a compound.

(3) Oxygen gas is slightly soluble in water.

(4) Oxygen gas can be compressed.

The statement that express the chemical property of oxygen from the question is that combination of Oxygen with a metal will  produce a compound.

(metal + oxygen → metal oxide)

(4Fe+ 3O2 → 2Fe2O)

Therefore, reaction of oxygen with metal will give a compound, hence option 2 is right

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Answer:

0.8910 mols of NaOH in a 35.65 g sample of NaOH

Explanation:

Mass off NaOH = 39.997

given = 35.65 g of NaOH

35.65 g of NaOH * 1 mol NaOH = 0.8910, since there are 4 sig figs.

                                /40.01 g

A 35.65 g sample of NaOH contains 0.8910 moles of NaOH.

The mole, denoted by the sign "mol," is the volume of a system that has the same number of atoms in 0.012 kilograms of carbon-12 as there are elementary particles.

The mole, often known as mol, is a SI unit used to measure how many particles are present in a given substance. A mole is made up of 6.02214179 atoms or other fundamental building blocks like molecules.

Mass off NaOH = 39.997

given = 35.65 g of NaOH

No of moles of NaOH =35.65 g of NaOH × 1 mol NaOH /40.01 g

No of moles of NaOH = 0.8910 moles.

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Answer:

To adjust the substance condition, you need to ensure the quantity of molecules of every component on the reactant side is equivalent to the quantity of particles of every component on the item side. To make the two sides equivalent, you should duplicate the quantity of particles in every component until the two sides are equivalent.

Explanation:

Answer:

c because it is a group of elements

Explaation:

Answer:

the answer is

removing seed casings from grains

removing salt from seawater

Explanation:

This question is regarding mixing and separating such as a physical change.

a soda bottle bubbling is a chemical reaction

copper statue is a chemical reaction

water decomposing to oxygen and hydrogen is also a chemical reaction

this question is talking about mixing and seperating as a physical change

Answer: 35. it is 100°C

36. there is 7 periods in the periodic table

37. A heterogeneous mixture consists of visibly different substances or phases. ... Solutions have particles which are the size of atoms or molecules - too small to be seen. Oil and water form a heterogeneous or cereal and milk also makes a heterogeneous. a example of solution mixture is salt and water or rubbing alcohol.

38.  A two phase mixture is a mixture of two different substances. An example of a two phase mixture would be a soft drink. It is a liquid and a gas. To separate these two substances you could heat the liquid and then capture the carbon dioxide.

Explanation:

I hope this helps you out buddy stay safe

Answer:

Explanation:

To find the volume when the pressure is at 202.6 kPa we use Boyle's law which is

[tex]P_1V_1 = P_2V_2[/tex]

where

P1 is the initial pressure

P2 is the final pressure

V1 is the initial volume

V2 is the final volume

Since we are finding the final volume

[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]

From the question

P1 = 99.3 kPa = 99300 Pa

V1 = 455 cm³

P2 = 202.6 kPa = 202600

So we have

[tex]V_2 = \frac{99300 \times 455}{202600} = \frac{45181500}{202600} \\ = 223.008390...[/tex]

We have the final answer as

Hope this helps you

Answer:

29. Proteins support the body's structural framework, chemical reactions, and contractions (muscle movement).

30. Proteins have a primary structure (polypeptide chain of amino acids), secondary structure (made up of alpha helices and beta pleat sheets), tertiary structure (superimposed on secondary structure), and quaternary structure (2 or more polypeptide chains with its own tertiary structure).

31. Protein molecules can denature if conditions aren't right, such as the wrong temperature or pH level. When denatured, proteins typically lose their shape and their function for a short time because their active sites become deactivated (though if conditions are too extreme, they can permanently lose their function). This happens to globular proteins because they are not nearly as stable as fibrous proteins due to their functional 3D shape.

I just did the first 3 since I could easily access the proteins section in my textbook at the moment. :)

Answer:

why is there air

Explanation:

it sounds more smarter and sounds like something someone would want to know

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\[/tex]

From the question

mass = 4.85 kg

volume = 280 cm³

We have

[tex]density = \frac{4.85}{280} \\ = 0.01732...[/tex]

We have the final answer as

Hope this helps you

Answer:

3 g/cm^3

Explanation:

Density can be determined by mass divided by volume, or P=m/V.

This would be 47.4 grams (mass) / 15.8 cubic centimeters (volume). The units are grams per cubic centimeter, noted as g/cm^3.

Answer:

a hypothesis

Explanation:

A hypothesis is a statement that is supposed or assumed before conducting any experiment. It is the assumption that is made on the basis of certain knowledge and controlled evidence in the initial time of the experiment. The initial assumption helps in taking the experiment or the investigation further. The truth is not ascertained in the initial phase rather the completion of the investigation is necessary to make a hypothesis turn into a theory.  

In the given situation, the statement given is a hypothesis because the use of the warm water for the growth of the plants is the assumption made with respect to the metabolism effect on the humans.

In a perfect world without air resistance, the top of the swing would have the most potential energy, but the least amount of kinetic energy. As the pendulum falls down, it gains more kinetic energy as it travels faster due to gravitational acceleration but loses more potential energy as it loses height. The total amount of energy in the system (the sum of kinetic and potential energy) stays the same.

The energy of a pendulum is changed from Kinetic to Potential Energy (and vice-versa) when it moves through one cycle of its motion.

The kinetic energy of an object is the energy that it possesses due to its motion and is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.

Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.

When we move the bob of the pendulum to start the movement you "charge" it with Potential Energy (Gravitational) by varying its position (height) in relation to the ground.

When we release the bob it moves towards the equilibrium position changing Potential into Kinetic Energy (through the movement with Velocity).

At the equilibrium point the bob doesn't stop but goes on up to the same height "re-charging" it with Potential Energy.

The sum of Kinetic (K) and Potential (U) Energy (called Mechanical Energy is always the same:

E = K + U = constant

Therefore, The energy of a pendulum is changed from Kinetic to Potential Energy (and vice-versa) when it moves through one cycle of its motion.

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Answer:

194.65 K

Explanation:

(−78.5 °C −109.3 °F)

Answer:

equal to the mass of the solid dry ice.

Explanation:

The mass of the gas is dependent on the mass of the solid dry ice.

Answer:

Explanation:

The second best answer is its group on the periodic table.

That answer depends on the actual reason. The number of protons determines which element you are talking about.

Answer:

D)

Explanation:

It is the most realistic

Answer:

He was able to count the number and type of butterflies that visited the garden,

Explanation:

Answer:

It will cost 45.37 US dollars (USD) to fill a 15 gallon gas tank in Canada.

Explanation:

Two values ​​are directly proportional when when one value increases, the other increases in the same proportion, or when one value decreases, the other decreases in the same proportion.

The rule of three makes it possible to solve proportionality problems effectively and quickly. It is a method of calculating an unknown value that is directly proportional to another known value.

Then, knowing the data a, b and c, and the fourth unknown data x, which will be the unknown to be solved, this value is calculated as:

a ⇒ b

c ⇒ x

So: [tex]x=\frac{c*b}{a}[/tex]

You must calculate the cost in US dollars (USD) to fill a 15 gallon gas tank in Canada. You know that the price of gasoline is $1.07 Canadian dollars (CAD) per liter. If 1 L equals 1.06 qts, then you can say that the price of gasoline is $ 1.07 Canadian dollars (CAD) per 1.06 qts.

You can now apply a rule of three as follows: if 4 qts is equal to 1 gal, 1.06 qts is equal to how much gal is?

[tex]gal=\frac{1.06 qts*1 gal}{4 qts}[/tex]

gal= 0.265

Then you can say that the price of gasoline is $ 1.07 Canadian dollars (CAD) per 0.265 gal.  So you can apply the following rule of three: if 0.265 gal costs $ 1.07 Canadian dollars (CAD), 15 gal how many Canadian dollars cost?

[tex]CAD=\frac{15 gal*1.07 CAD}{0.265 gal}[/tex]

CAD= $60.8 CAD

Finally, you can apply the following rule of three: if $ 1.34 (CAD) is equal to $ 1.00 (USD), $ 60.8 (CAD) is equal to how many US dollars (USD)?

[tex]USD=\frac{60.8 CAD*1USD}{1.34 CAD}[/tex]

USD=   45.37

It will cost 45.37 US dollars (USD) to fill a 15 gallon gas tank in Canada.

Answer: okay

Explanation:

Answer:

What exactly do you want help with

Explanation:

Answer:

its help us

equation- ( a)2+(b)2+2an

In model of molecules, gray spheres are carbon atoms, white spheres are hydrogen atoms , red spheres are oxygen atoms and blue spheres are nitrogen atoms. the model represent a molecule of NH₃ is model (A) that contains one blue sphere and 3 white sphere.

Ammonia (NH₃ ) is formed  with three atoms of hydrogen and one atom of nitrogen. In the molecule of NH₃ , three hydrogen atoms each shares their electron with nitrogen and form the covalent bond and molecule is formed NH₃ . in the given model (A) 3 white spheres of hydrogen are covalently bonded with one blue sphere of nitrogen.

Thus, In model of molecules, gray spheres are carbon atoms, white spheres are hydrogen atoms , red spheres are oxygen atoms and blue spheres are nitrogen atoms. the model represent a molecule of NH₃ is model (A) that contains one blue sphere and 3 white sphere.

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Answer:

The photographic evidence of a long-unseen cosmic force is an extraordinary achievement in science. ... Exciting as it is, the photo actually doesn't capture the black hole itself, nor its interior. Astronomers aimed their telescopes at the event horizon, the invisible boundary thought to surround all black holes

Explanation:

Hope this helps :)

Answer:

B. Istope

Explanation:

Answer:

idk

Explanation:

Answer:

The mass of water is known to be 1 g/mL or 1 g/cm3. If an object has a density greater than 1 g/cm3, it is denser than water and will sink. If it has a density of less than 1 g/cm3, it will float. For example, a penny is made out of zinc (7.14 g/cm3) and copper (8.96 g/cm3) so it sinks in water.

Explanation:

Answer: i think b.

Explanation:

Answer:

5625000gm/cm^3

Explanation:

volume=w*h*l=25*15*5=1875cm^3

density=mass*volume

=1875*3000

=5625000gm/cm^3