Im sorry if its difficult to read


we dont talk about how I messed up my first question and jad to make another one because im slow​

Explanation:

reduction in the number or quantity of something.

"the depletion of the ozone layer" is called depletion

Answer:

A

Explanation:

The instrument in which the washer works as a valve is  A ; syringe

Each instrument listed have a washer and a valve, but of all the instruments listed above the instrument that its washer works also as a valve is the syringe.

A syringe is composed of a thin tube and a thinner hollow needle attached to the end of the thin tube. the needle is used and take in liquids and also expel liquids from the syringe ( i.e. washer and valve )

hence the instrument that its washer also functions as a valve is the syringe.

learn more about syringe : https://brainly.com/question/24283167

Answer:

132.17amu

Explanation:

(14.01+1.01 multiplied by 4)=18.05×2=36.1

36.1+32.07= 68.17

16.00×4=64

68.17+64=132.17

Answer:

132.17 amu

Explanation:

just took the test. got 100

Answer:

2500grams

hope this helps

Answer: 2500 gram

Explanation:

Concept:

Here, we need to know the idea of unit conversion.

Unit conversion is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.

1 kg = 1000 g

Solve:

1kg = 1000g

2.5kg = 2.5 × 1000 = 2500g

Hope this helps!! :)

Please let me know if you have any questions

Answer:

One way to predict the type of bond that forms between two elements is to compare the electronegativities of the elements. In general, large differences in electronegativity result in ionic bonds, while smaller differences result in covalent bonds. the bonding is covalent bcz its between the most electronegative atom nitrogen and carbon .

Since the electronegativity difference between nitrogen and chlorine is not very much so chemical bonding is the only bond between them Thus the name of  N2C14 is Dinitrogen Tetrachloride and there is covalent bonding in this compound

There are two types of bonding in chemistry, one is ionic bonding while other is covalent bonding. Ionic bonding is due to the complete transfer of electron from one  element to other. While the covalent bond is due to the equal sharing of electron by each element

Metals and non metals combine to form ionic bond while the element with the same electronegativity form covalent bonding.

To name this we have to see the number of element and accordingly use di, tri and the write the name of first element and then second element's name with ide

Thus the name of  N2C14 is Dinitrogen Tetrachloride and there is covalent bonding in this compound

To know more about chemical bonding, here:

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Answer:

BHAI SECOND OPTION HOGA

Answer:b

Explanation:

1. Cl2 + H2O → HOCl + HCl

2. Tooth decay starts when when the pH of the mouth is lower than 5.5. Tooth enamel is made up of calcium phosphate and it is one of the hardest substances of the body. But it is corroded when the pH is less than 5.5. The bacteria of our mouth produce acids by degradation of sugar and food particles remaining in our mouth after eating food.

3. Fluorine salts are added in toothpaste to protect our teeth from tooth decay. Fluorine salts are mildly basic, so they neutrelise the acid in our mouth that leads to tooth decay.

4. Tincture of iodine is iodine, pottasium iodide and sodium iodide dissolved in ethanol. Iodine acts in an antiseptic manner by destroying microbial proteins and DNA.

5. Tincture of iodine is clear and reddish brown liquid.

Answer:

C

Explanation:

I hypothesis needs to be tested to know whether it is true or not. Here is the definition:

A supposition or proposed explanation made on the basis of *limited evidence as a started point for further investigation*

Answer:

The Cavendish experiment, performed in 1797–1798 by English scientist Henry Cavendish, was the first experiment to measure the force of gravity between masses in the laboratory and the first to yield accurate values for the gravitational constant

Explanation:

I think that's correct

Answer:

1.Physical change

2. Chemical change

3. Heat

4.photosynthesis

5. composition

Answer:

A water molecule is composed of two hydrogen atom and one oxygen atom but you can't simply take two hydrogen atom stick them onto an oxygen atom

Answer:

since there are no lone pairs on the central atom, this would be a trigonal planar molecule. It's polar because the shape of it does not cancel its polarity (you can think of it as not having a balanced electronegativity pull, since the nitrogen is pulling on one side, and the oxygens are pulling on the other. It would be nonpolar if the there were 3 Oxygens).

Sorry this take a little bit long. I was a little confused by the odd valence number

Answer:

Las bebidas gaseosas como las gaseosas están hechas de un soluto de dióxido de carbono gaseoso en un líquido. La solubilidad del dióxido de carbono en el líquido depende de la presión y la temperatura de la lata de refresco, y también de agitar la lata de refresco que introduce burbujas que permanecen ocultas hasta que se abre la lata antes de que burbujee.

Por lo tanto, dado que la presión en la lata de refresco permanece constante, elevar la temperatura, agitar la lata de refresco o congelar el refresco, lo que aumenta la cantidad de dióxido de carbono en la porción líquida, hará que el refresco forme espuma y se derrame.

Explanation:

Answer:

29.41% of Calcium and 47.04% of Oxygen

Explanation:

The percent composition of an atom in a molecule is defined as 100 times the ratio between the mass of the atom and the mass of the molecule.

The mass of the molecule of the problem (Ore) is 46.28g. That means the percent composition of Calcium is:

13.61g / 46.28g * 100 = 29.41% of Calcium

And percent composition of Oxygen is:

21.77g / 46.28g * 100 = 47.04% of Oxygen

Answer:

We know that an antacid is a base that can neutralize the stomach acid when ingested. The student observed that a soluble antacid tablet reacted faster in relieving pain due to the excess acid secreted in the stomach. So, the problem that can be studied is the effect of temperature on the rate of neutralization of stomach acid by the antacid. The independent variable is the one the student is going to vary that is the temperature. The dependent variable is the rate of reaction or the time taken for an antacid tablet to neutralize the acid present in stomach. The controlled variable is the tablet taken, that is the student should use a specific antacid tablet to ensure that the rate of reaction or the time taken for the antacid tablet to neutralize the acid present in stomach is not affected by the chemical composition of tablet.

Explanation:

Hope u understood.

Answer:

The correct answer is - D. Freezing point depression.

Explanation:

When rock salt is spread over snow-covered icy roads, it generates a liquid layer over it by melting from the surface thereby lowering or depression in the freezing point below the ice.

Therefore, due to this liquid layer comes into the contact with the ice present on the road and causes other ice to melts. This keeps on decreasing the volume of the ice on the road therefore, rock salts spread on the roads during a snowstorm.

Answer:

36.02g bbbbbbbbbbb hbbnjkkkj

Answer:

36.02g

Explanation:

Hope this helps!

Answer:

0.017g/mol

Explanation:

according to the mole concept to calculate the number of moles of a substance you use the formula

number of moles= mass/molecular mass

=4.5g/254g/mole

=0.017moles

I hope this helps and sorry if it's wrong

Answer:

Initial temperature, T1 = 99.4 Kelvin

Explanation:

Given the following data;

To find the initial temperature (T1), we would use Charles' law;

Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.

Mathematically, Charles' law is given by the formula;

[tex] \frac {V}{T} = K [/tex]

[tex] \frac {V_{1}}{T_{1}} = \frac {V_{2}}{T_{2}} [/tex]

Making T1 as the subject formula, we have;

[tex] T_{1} = \frac {V_{1}T_{2}}{V_{2}} [/tex]

Substituting the values into the formula, we have;

[tex] T_{1} = \frac {65.8 * 200}{132.4} [/tex]

[tex] T_{1} = \frac {13160}{132.4} [/tex]

Initial temperature, T1 = 99.4 Kelvin

The answer is zero also I suggest googling the questions there is a quizlet with the answers

Answer:

Divide the mass of the solute by the total volume of the solution. Write out the equation C = m/V, where m is the mass of the solute and V is the total volume of the solution. Plug in the values you found for the mass and volume, and divide them to find the concentration of your solution.

Answer:

Triads were groups of 3 elements with similar chemical and physical properties. Beryllium, magnesium, and calcium are all earth alkalis found in the earth

Explanation:

Answer:

This is the answer

C-H, Br-H, F-H, LI-CI, Na-CI, K-F

Hope this helps.

Explanation:

Both sodium and potassium belong to the same group. They both have only one electon in their outermost shell. But they belong to different periods. Sodium has 3 shells while potassium has 5. As the distance between the valence electron and the nucleus is more in potassium. It experience lesser pull by the nucleus and so can give away the valence electron very easily as compared to sodium which experience a greater pull from the nucleus. Thus potassium is more reactive. Reactivity increases on moving down the group.

Answer:

Sodium and potassium belongs to same group . Both has 1 electron to donate but sodium is less reactive because nuclear attraction makes it little bit difficult to loose electron as compared to potassium in which nuclear attraction becomes unable to pull the electrons towards itself . Hence we easily remove electron moreover due to screening effect also takes place .

Explanation:

Plant cells have several structures not found in other eukaryotes. In particular, organelles called chloroplasts allow plants to capture the energy of the Sun in energy-rich molecules; cell walls allow plants to have rigid structures as varied as wood trunks and supple leaves; and vacuoles allow plant cells to change size.

The cell wall is located outside the cell membrane. It consists mainly of cellulose and may also contain lignin , which makes it more rigid. The cell wall shapes, supports, and protects the cell. It prevents the cell from absorbing too much water and bursting.

Answer:

A). 2.1 × [tex]10^{-2}[/tex]

Explanation:

Given reaction,

2[tex]HF[/tex] (g) ⇄ [tex]H_{2}[/tex] (g) + [tex]F_{2}[/tex] (g)

The concentrations are as following;

[tex]HF[/tex] = 5.82 × [tex]10^{-2}[/tex] M

[tex]H_{2}[/tex] = 8.4 × [tex]10^{-3}[/tex] M

[tex]F_{2}[/tex] = 8.4 × [tex]10^{-3}[/tex] M

So,

[tex]K_{eq}[/tex] = [([tex]H_{2}[/tex] ) × ([tex]F_{2}[/tex])] ÷ [[tex]HF[/tex]]^2

Now,

We can determine the value of [tex]K_{eq}[/tex] by substituting the values in above formula:

[tex]K_{eq}[/tex] = [ (8.4 × [tex]10^{-3}[/tex] M) × (8.4 × [tex]10^{-3}[/tex] M)] ÷ [(5.82 × [tex]10^{-2}[/tex])^2

= 2.08 * [tex]10^{-2}[/tex]

=  2.1 × [tex]10^{-2}[/tex]

∵ [tex]K_{eq}[/tex] = 2.1 × [tex]10^{-2}[/tex]

Thus, option A is the correct answer.

Answer:

[tex]\boxed {\boxed {\sf 8.38 \ L}}[/tex]

Explanation:

We are asked to find the new volume of a gas after a change in temperature. We will use Charles's Law, which states the volume of a gas is directly proportional to the temperature. The formula for this law is:

[tex]\frac {V_1}{T_1}= \frac{V_2}{T_2}[/tex]

The gas starts at 100 degrees Celsius and a volume of 33.5 liters. Substitute these values into the formula.

[tex]\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{T_2}[/tex]

The gas is cooled to 25 degrees Celsius, but the volume is unknown.

[tex]\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{25 \textdegree C}[/tex]

We want to find the volume of the gas after it is cooled.  We must isolate the variable V₂. It is being divided by 25 degrees Celsius and the inverse of division is multiplication. Multiply both sides of the equation by 25 °C.

[tex]25 \textdegree C*\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{25 \textdegree C}* 25 \textdegree C[/tex]

[tex]25 \textdegree C*\frac {33.5 \ L}{100 \textdegree C}= V_2[/tex]

The units of degrees Celsius cancel.

[tex]25*\frac {33.5 \ L}{100 }= V_2[/tex]

[tex]8.375 \ L = V_2[/tex]

The original measurements have 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 5 in the thousandths place tells us to round the 7 up to an 8.

[tex]8.38 \ L \approx V_2[/tex]

The new volume after the gas is cooled is approximately 8.38 liters.