Why is it useful to know the background level of extinction?

It is part of the scientific process to observe changes in nature.

If current rates greatly exceed background rates, scientists say there is a chance of a
mass extinction event happening.

NOAA and FWS are required by law to compare background rates to current rates.

Scientists want to see if increased extinction rates will threaten the human population.

Answer:

[tex]H _{3}O {}^{ + } [/tex]

Hydroxonium ion

Answer:

Sodium bicarbonate.

Explanation:

The gas produced during the mixing of bath bombs in water is Sodium bicarbonate. If the reaction is with citric acid then Sodium citrate can be produced. They are weak acid with bicarbonate base. These bath bombs can be a mixture of wet and dry substances and any shape can be mold.

Answer:

4. oxygen gas

Explanation:

when a plant goes through photosynthesis, it takes in Carbon Dioxide and releases Oxygen

Answer:

the digestive system

Explanation:

The digestive system is the stomache

it breaks down the food

makes glucine

creates energy

Stomach

Explanation:

When food enters your stomach, it mixes the foods and liquids with digestive juices.

The details of the galvanic cells are missing so i have attached it.

Answer:

The voltage will increase in cell Y and decrease in cell Z.

Explanation:

Looking at the reaction, in half cell 3, we see that reduction takes place in galvanic cell Y while oxidation takes place in galvanic cell Z.

In galvanic cell Y, aluminum gains electrons which is reduction while in galvanic cell Z, Copper loses electrons which is oxidation.

Now, electricity involves movement of electrons and where there is a loss of electrons, it means a decrease in electricity and when there is a gain in electrons, it means there is an increase in electricity.

Now, in electricity, Voltage is directly proportional to electric power.

Thus, the higher the voltage, the higher the electric power.

Thus, in galvanic cell Y that undergoes gain in electrons, there will be an increase in voltage while in galvanic cell Z that undergoes loss of electrons, there will be a decrease in voltage.

The molar mass of the gas is 65.3 g/mol

The number of mole of the gas can be obtained by using the ideal gas equation as illustrated below:

PV = nRT

Divide both side by RT

n = PV / RT

n = (1.04 × 0.854) / (0.0821 × 302)

n = 0.0358 mole

Molar mass = mass / mole

Molar mass = 2.34 / 0.0358

Molar mass of gas = 65.3 g/mol

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Answer:

65.3 g/mol

Explanation:

use the ideal gas law with molar mass formula

M = mRT/PV

m= 2.34 g

V = 0.854 L

T = 302k

P = 1.04

R = 0.0821

just plug those in and solve

Answer:

K2 +Br ->2KBr

K + I ->KI

actually I don't know the e option but I had tried can u pls balance it urself

Answer:

D. KOH + HBr will give KBr + H2O

E. KOH + HI will give KI + H2O

Answer: A lower temperature slows down the reaction that causes souring, making the milk last longer in the refrigerator.

Explanation:

Milk is made up of different constituents which includes:

--> water,

--> fat,

--> proteins,

--> lactose (milk sugar) and minerals (salts).

Milk is also considered to be a heterogeneous mixture because of the presence of fat and water which are two immiscible liquid phases that are present.

Milk contains a sugar called lactose. It also contains harmless bacteria called lactobacillus, which uses lactose for energy and creates lactic acid as a by-product. It is the lactic acid which makes milk taste sour. Therefore when milk is kept at a LOWER temperature, these bacteria growths are limited but at a HIGHER temperature such as room temperature, the growth is increased. As they increase in growth, the bacteria makes use of the lactose for energy and creates lactic acid as a by-product as earlier mentioned, leading to the sour taste observed.

Answer: The mass of barium nitrate required is 23.91 g

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]    ......(1)

Given mass of sodium phosphate = 10.0 g

Molar mass of sodium phosphate = 163.94 g/mol

Plugging values in equation 1:

[tex]\text{Moles of sodium phosphate}=\frac{10.0g}{163.94g/mol}=0.061 mol[/tex]

The chemical equation for the reaction of sodium phosphate and barium nitrate follows:

[tex]3Ba(NO_3)_2+2Na_3PO_4\rightarrow Ba_3(PO_4)_2+6NaNO_3[/tex]

By the stoichiometry of the reaction:

If 2 moles of sodium phosphate reacts with 3 moles of barium nitrate

So, 0.061 moles of sodium phosphate will react with = [tex]\frac{3}{2}\times 0.061=0.0915mol[/tex] of barium nitrate

Molar mass of barium nitrate = 261.337 g/mol

Plugging values in equation 1:

[tex]\text{Mass of barium nitrate}=(0.0915mol\times 261.337g/mol)=23.91g[/tex]

Hence, the mass of barium nitrate required is 23.91 g

Answer:

Answer:

Kc = 0.20        

Explanation:

                 N₂O₄     ⇄    2NO₂

moles       5.3mol          2.3mol

Vol               5L                5L

Molarity    5.3/5M        2.3/5M

               = 1.06M     = 0.46M

Kc = [NO₂]²/[N₂O₄] =  (0.46)²/(1.06) = 0.1996 ≅ 0.20

Note:

All credit goes to  drpelezo (Ace) who created and explained the answer.

Have a nice day, and I hope this helps

-kiniwih426

Answer:

friend me on here and imma send you the link Explanation:

Answer:

I think that temperature will be cut in half.

When volume increases, pressure decreases. As pressure decreases, temperature decreases. So if you double volume, pressure is halved and so will the temperature. I'm new to this, but I think that's the answer . Tell me if I'm right good luck!

Answer:

Resistance

Explanation:

Resistance is the measure of the opposition of current in a circuit.

Answer:

Increasing the temperature

Explanation:

The rate of solubility depends on a few factors. By increasing the temperature, the kinetic energy of the particles increase, leading to a higher rate of diffusion, dissolving the solid solute quicker.

[tex]\huge{ \mathrm{  \underline{ Answer} \:  \:  ✓ }}[/tex]

The Correct option is :

[tex] \large \boxed{\mathrm{B.}}[/tex]

The particles diffuse from the region of higher concentration to the region of lower concentration.

for example :

during Inhalation, oxygen is in higher concentration in our lungs but in lower concentration blood capillaries, so oxygen diffuses into the blood and carbon dioxide which is in higher concentration in blood diffuses out from the blood capillaries.

_____________________________

[tex]\mathrm{ ☠ \: TeeNForeveR \:☠ }[/tex]

Inside the balloon, the gas particles collide with the balloon's inner walls. ... As the molecules heat up, they move faster and strike the inside wall of the balloon harder. This increased motion of the gas particles increases the force on an area of the balloon, producing a rise in the pressure.

mark me brainliestttt :))

Explanation:

The mass of one mole of a substance, expressed in gms, is equal to the mean molecular mass of the substance. The molecular mass of CO2= 12+2x16= 44 so the mass if a mole of CO2 is approximately 44 grams.

Hope it helps!!!...

Please mark it as brainliest...

Answer:

11.0 L

Explanation:

Podemos resolver este problema usando la ley de Charles, que afirma que a presión constante:

Donde el subíndice 1 indica las condiciones iniciales y el 2 las finales. En este caso:

Introducimos los datos:

Y calculamos V₂:

Answer:

1.94 moles

Explanation:

because moles =mass/mr

=34.9/18

which gives 1.938 so we round it up to 1.94

mr of H2O is 18

hope this helps :)

1.94 moles of water in 34.9 g of water.

It is defined as given mass over molar mass.

Molar mass = 18 g/mol

Number of moles  =  Given mass  /  Molar mass

Number of moles = 34.9 g / 18 g/mol

Number of  moles = 1.94 moles

Thus, 1.94 moles of water in 34.9 g of water.

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Answer:

Autotrophs have the ability to synthesize their own food from the substances surrounding them. Examples of this are photosynthesis or chemical energy. Heterotrophs cannot synthesize their own food. They have to get their nutrition from other animals or plants.

In shorter terms, autotrophs are plants. Heterotrophs are humans.

Explanation:

Answer:

Alpha

Alpha decay

When a nucleus emits an alpha particle, these changes happen: the mass number decreases by 4.

Answer:

2.18 grams of Br2 reacts to produce 3.25 grams of KBr

Explanation:

The balanced equation is

2 KI + Br2 → 2 KBr + I2

2 moles of KI and 1 mole of Br2 reacts to produce two molecules of KBr

Mass of two moles of KI = 2 * 166 grams

Mass of one mole of Br2 = 159.808 grams

Mass of two moles of KBr = 2* 119 grams

Thus,  159.808 grams of Br2 reacts to produce 2* 119 grams of KBr

2.18 grams of Br2 reacts to produce {(2* 119)/ 159.808} * 2.18 grams of KBr

2.18 grams of Br2 reacts to produce 3.25 grams of KBr

2 F atoms

Explanation:

A Ca atom has a valence number of +2, which means that when ionized, it will give up two electrons. In turn, a F atom has a valence number of -1, which means it can only accept 1 electron when ionized. So to accommodate the two electrons from Ca atom, we need 2 F atoms.

Answer:

Unsaturated

Explanation:

An unsaturated solution contains less solute than it can normally hold at a particular temperature.

This kind of solution can also dissolve more solute.

Hence, when a bit of solute is added to this solution, the solute dissolves indicating that the original solution was unsaturated.

Answer:

Though a hydrogen atom has only one electron, it contains a large number of shells, so when this single electron jumps from one shell to another, a photon is emitted, and the energy difference of the shells causes different wavelengths to be released... hence, mono-electronic hydrogen has many spectral lines.

Explanation:

thank me later

The reason that the atomic emission spectrum of hydrogen contains only four lines is the hydrogen atoms form a continuous series of quantized energy levels that transmute at a variety of frequencies.

The emission spectrum of hydrogen consist of numerous spectral series, the wavelength is postulated by Rydberg formula.

The reason behind the lines of spectrum is the transition of electron between two energies.

Thus, the correct option is A.

Learn more about atomic emission

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Answer:

[tex]0.64molCr(NO_3)_3[/tex]

Explanation:

Hello there!

In this case, according to the given chemical equation, it turns out possible for us to realize there is a 4:3 mole ratio of chromium(III) nitrate to lead(IV) nitrate, and therefore, we can calculate the moles of the former by applying the shown below stoichiometry setup:

[tex]0.85molPb(NO_3)_4*\frac{3molCr(NO_3)_3}{4molPb(NO_3)_4} \\\\0.64molCr(NO_3)_3[/tex]

Regards!