A substance is on its fifth half-life. Which approximates the percentages of radioactive and stable isotopes, respectively? 96.9%; 3.1% 3.1%; 96.9% 12.5%; 87.5% 87.5%; 12.5% Need an answer fast

Answer:

It emits hydrogen sulfide...smells like rotten eggs..

ty:)pls let me know whether this is ryt:D

Answer:

Hey!

Your answer is that it creates hydrogen sulfide gas / liquid...

Which really smells...

Explanation:

HOPE THIS HELPS!

Answer:

The answer is C

Explanation:

Aluminium oxide is an amphoteric oxide.

MgO is a basic oxide.

N2O is an acidic oxide.

SO2 is an acidic oxide.

Answer:

B - Poor crop production

Explanation:

I just did the quiz on Edge 2021

Answer:

b

Explanation:

Answer:

higher temperatures increase the speed of solubility

Explanation:

This is because if the temperature of liquid is high and you place a solute inside it dissolves faster than a low temperature

Higher temperature increases the speed of solubility affect the speed with which the solute dissolves. Therefore, option A is correct.

The term solubility is defined as the maximum amount of a substance that will dissolve in a given amount of solvent at a specific temperature.

Based on the concentration of solute dissolves in a solvent, solutes are divided into highly Soluble, sparingly Soluble or insoluble substance.

When a solvent is heated, the molecules gain kinetic energy. Because of the increased rapid motion, the solvent molecules collide with the solute more frequently and with greater force. Both factors accelerate the solute's dissolution.

This is because if the temperature of the liquid is high and a solute is placed inside, the solute dissolves faster than if the temperature is low.

Thus, option A is correct.

To learn more about the solubility, follow the link;

https://brainly.com/question/29661360

#SPJ6

Answer:

You have 1680 grams of urea. It means (in it) there are 787 grams of nitrogen, 112 grams of hydrogen, 336 grams of carbon, and 448 grams of oxygen.

Explanation:

Answer:

37.1g of Ca

Explanation:

Hello,

Molecular formula for calcium chloride = CaCl

Molar mass = 40 + 35.5 = 75.5g/mol

Assuming there's one mole of CaCl

1 mole = mass / molar mass

Mass = 1 × 75.5

Mass = 75.5g

75.5g of CaCl contains 40g of Calcium

70g of CaCl will contain x g of Calcium

X = (70 × 40) / 75.5

X = 37.086g

Therefore, 70g of CaCl contains approximately 37.1g of Ca

Answer:

Explanation:

1) Chemical change :

It is permanent change.

Heat or energy is given out during the process

Physical change :

It is a temporary change.

Heat or energy in not given out during the process.

2) Condensation of water vapour is a physical change.

hope this helps

plz mark it as brainliest!!!!!!!

Answer:

i. The difference between physical and chemical change is that a physical change merely changes the shape and size of the substance while a chemical change produces altogether new substance.

ii condensation of water vapour is a physical change

Explanation:

Answer:

this option is the correct they move to an area with lower oxygen concentration because gas molecules can pass through semi-permeable and do not need transport proteins for the movement

Explanation:

i hope this will help you

can confirm that

They move to an area with a lower oxygen concentration

if the correct answer :)))

Explanation:

ape-x

Answer:

B and BBr3

Explanation:

1) 3HBr + B = BBr3 + H2 (double all equation because H2)

2) 6HBr + 2B = 2BBr3 + 3H2

Answer: When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.

Explanation:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The overall chemical reaction follows:

[tex]CaO(s)+CO_2\rightarrow CaCO_3(s)[/tex]     [tex]\Delta H^o_{rxn}=?[/tex]

The intermediate balanced chemical reaction are:

(1) [tex]Ca(s)+CO_2(g)+\frac{1}{2}O_2(g)\rightarrow CaCO_3(s)[/tex]    [tex]\Delta H_1=-812.8kJ[/tex]  

(2) [tex]2Ca(s)+O_2(g)\rightarrow 2CaO(s)[/tex]     [tex]\Delta H_2=-1269kJ[/tex]

The expression for enthalpy of the reaction follows:

[tex]\Delta H^o_{rxn}=[1\times (\Delta H_1)]+[\frac{1}{2}\times (-\Delta H_2)][/tex]

Hence, when the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.

Answer:

A. is halved and has its sign changed.

Explanation:

just took the test on edge

Answer:

A. 1s²2s²

B. 1s²

C. 1s²

D. 1s²2s²2p⁶

Explanation:

The valency electron is the outer electron of an element. The valency electron resides in the outermost region of the shell.

Using the general configuration for the first 20 elements 2 8 8 2 the valency electrons can be identified.

A. 1s²2s²2p⁶3s² . The valency electron here are 2p⁶ and 3s² . Removing the valency electron we have 1s²2s²

B. 1s² 2s² 2p⁶. After removing the valency electron the configuration will be 1s².

C.1s²2s². After removing the valency electron the configuration will be 1s²

D.1s²2s²2p⁶3s¹. Removing the valency electron the electron configuration will be 1s²2s²2p⁶

Answer: The phenomenon of osmosis can be seen in the surrounding as the when the raisins are put into water overnight. The water enters the raisins and it swells.

The osmosis can be defined as the biological phenomenon by which the water or any other liquid enters from an area of its higher concentration to an area of its lower concentration via semi permeable membrane.

Diffusion can take place in between gases and in between gases and liquid.

Exchange of gases in the lungs is an example of diffusion in liquids and burning an incense stick in the room is an example of diffusion in gases.

Answer:

it is Ph of solution that tells you the acdic and basic nature of solution

if PH is lower than 7 the soution is acidic and if PH is larger than 7  the solution is basic

Explanation:

Answer:

A. Ph

Explanation:

Answer:

234.9 grams

Explanation:

Hope this helps

Answer:

210

Explanation:

according to vectors since they are in two different direction u minus them

F1 =10 F2=220

F1 has a forward direction

while f2 goes backward

Answer:

-210N

Explanation:

you say acting force minus opposing force 10N-220N= -210N

Answer:

The answer is 17.75%.

Explanation:

We are given [tex]NH_{3}[/tex] (ammonia) as a chemical formula. We want to find the percent composition of the formula.

We are given the atomic masses of each element: [tex]H = 1.008 amu[/tex] and [tex]N = 14.01 amu[/tex]. Then, we need to find out how many atoms are present of each element in the compound.

N has one atom (no subscript present). H has three atoms (subscript of 3 is present).

Now, we simply multiply the masses of each element by the number of atoms present of that element.

[tex]H = 1.008amu * 3atoms = 3.024amu[/tex]

[tex]N = 14.01amu * 1 atom = 14.01 amu[/tex]

Then, we add up those products to get the mass of the formula.

[tex]3.024amu + 14.01amu = 17.034amu[/tex]

Finally, we divide the masses of each element by the mass of the formula to get the percentages of each element present in the compounds.

For hydrogen:

[tex]\frac{3.024amu}{17.034 amu} =0.1775[/tex]

[tex]0.1775 * 100 = 17.75[/tex]

Hydrogen atoms account for 17.75% of the compound.

For nitrogen:

[tex]\frac{14.01amu}{17.034amu} = 0.8225[/tex]

[tex]0.8225 * 100 = 82.25[/tex]

Nitrogen atoms account for 82.25% of the compound.

For an extra step, add up the percentages to make sure you get within 100 ± 0.01. Otherwise, you may have rounded incorrectly or miscalculated somewhere within your work.

Hope this helps!

Answer:

acid rain

Explanation:

When sulfur dioxide combines with water and air, it forms sulfuric acid, which is the main component of acid rain. Acid rain can: cause deforestation.

Answer:

They are all alkali earth metals.

Explanation:

Their valence shell each has 2 electrons. Also, they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure. They form alkaline solutions, hydroxides, when reacting with water and their oxides are found in the earth’s crust.

Answer:

magnesium (Mg)

Explanation:

Answer:

The entropy of this reaction (ΔS) = -187.9 J/K

Explanation:

.Step : Data given

ΔS = -187.9 J/K

ΔH = -198.4 kJ

T = 297.0 K

Step 2: The balanced equation

2SO2(g) + O2(g) → 2SO3(g)

Step 3: Calculate the entropy

ΔG = ΔH - TΔS

⇒ΔG = the gibbs free energy

⇒ΔH = the change in enthalpy of the reaction = -198.4 kJ

⇒with T = the temperature = 297.0 K

⇒with ΔS = the change of entropy =  -187.9 J/K

ΔG = -198400 kJ -297*(-187.9kJ/mol)

ΔG = -198400+55806.3

ΔG = - 142593.7 kJ = the gibbs free energy

The entropy of this reaction (ΔS) = -187.9 J/K

Answer:

C. -187.9 J/K

Explanation:

Entropy is just ΔS, which it gives you in the question as -187.9 J/K.

Answer:

It's A) magnesium bromide

Explanation:

The name for the compound MgBr2 is magnesium bromide. Mg is the symbol for magnesium, and Br is the symbol for bromine.

I Hope it will help

Answer:

10⁻³⁶ s

Explanation:

There is much speculation, but many scientists believe the universe started expanding about 10⁻³⁶ s  after the Big Bang.

Answer:

-169°C to -104°C

Explanation:

Ethene, also known as ethylene exists in solid, liquid and gaseous states. Ethene is an aliens with condensed structural formula C2H4. Athens is a colourless gas. It is flammable and is also a sweet smelling gas in its pure form. It is the monomer in the production of polyethylene which is of great importance in the plastic industry. In agriculture, it is used to induce the ripening of fruits. It can be hydrated in order to produce ethanol.

The liquid range of ethene refers to the temperatures at which ethene is found in the liquid state of matter. It is actually the difference between the melting point and the boiling points of ethene. Hence the liquid range of ethene is -169°C to -104°C

Answer:

Fabric is made of cotton.

Explanation:

Hope that helps :)

Answer:

Hey mate your answer is

cotton

hope it helps you

mark as brainlist

Answer: Water, alcohols, aldehydes, and ketones.

Explanation:

Answer:

Examples of Partially Miscible and Immiscible Liquids: Illustrations of immiscible liquids are cooking oil and water, milk and oil, gasoline and water, and liquid metals and water. There are as well partially miscible liquids such as honey and water, butanol and water, and potassium chloride and water.

Explanation:

Hope it helps

Answer:

this is the answer

Explanation:

If someone tells Atomic mass of oxygen is 16, then it means that One the mass of an atom of a oxygen expressed in atomic mass units is 16 It is approximately equivalent to the number of protons and neutrons in the atom of oxygen (the mass number) or to the average number allowing for the relative abundances of different isotopes of oxygen.

Atomic mass Of oxygen is 15.99u or 15.99 amu.

And the mass no. Of oxygen is 16 because total no. Of protons and neutrons (in oxygen 16) is 16.

8 protons+ 8neutrons

So we can say that mass no. And atomic mass are different things.

Then, the atomic mass of oxygen is not 16 rather 15.99amu or 15.99u

Answer: The total pressure of the mixture is 2.76 atm

Explanation:

According to Dalton's law, the total pressure is the sum of individual pressures.

[tex]p_{total}=p_A+p_B+p_C...[/tex]

Given : [tex]p_{total}[/tex] =total pressure of gases = ?

[tex]p_{O_2}[/tex] = partial pressure of oxygen = 0.00461 atm

[tex]p_{N_2}[/tex] = partial pressure of nitrogen = 1.78 atm

[tex]p_{Ar}[/tex] = partial pressure of argon = 0.975 atm

putting in the values we get:

[tex]p_{total}=0.00461atm+1.78atm+0.975atm[/tex]

[tex]p_{total}=2.76atm[/tex]

Thus the total pressure of the mixture is 2.76 atm

Answer:

112mL

Explanation:

We'll begin by calculating the number of mole in 0.640g of SO2.

This is illustrated below:

Molar mass of SO2 = 32 + (16x2) = 64g/mol

Mass of SO2 = 0.640g

Number of mole of SO2 =.?

Mole = mass /molar mass

Number of mole of SO2 = 0.640/64

Number of mole of SO2 = 0.01 mole

Next, we shall determine the number of mole of O2 required for the reaction. This is illustrated below:

2SO2(g) + O2(g) —> 2SO3(g)

From the balanced equation above,

2 moles of SO2 reacted with 1 mole of O2.

Therefore, 0.01 mole of SO2 will react with = (0.01 x 1)/2 = 0.005 mole of O2.

Therefore, 0.005 mole of O2 is required for the reaction.

Finally, we shall determine the volume of O2 required for the reaction as follow:

Note: 1 mole of a gas occupy 22.4L (22400mL) at stp.

1 mole of O2 occupy 22400mL at stp.

Therefore, 0.005 mole of O2 will occupy = 0.005 x 22400 = 112mL

Therefore, 112mL of O2 is required for the reaction.

Answer:

the answer is C

Explanation:

i did the test on edg and got it right