Which of these changes is an example of a chemical change?

A. ice cream solidifying.
B. a tree decomposing in a forest.
C. a figure made from a block of modeling clay. D. polishing a gemstone. ​

Answers

Answer 1

The answer is B. It's the only one in which the original mass changes to a different mass.


Related Questions

What is an extinct species? *
(10 Points)
O A. a species that blends in easily with its environment
O B. a species that resembles another species
O C. a species that was unable to adapt and died out
O D. a species that is bred for specific characteristics

Answers

Answer: C

Explanation: I got it right.

Give the coefficient of y in the following expression. 2xz² - 7xy + 4.​

Answers

Answer:

the coefficient of y is -7

an alloy is a metal that has?

Answers

An alloy always has two or more elements/metals in it. An alloy always has at least metal in it.

Steels have iron and carbon in it. Bronze is copper and tin, or aluminum, or manganese, or zinc. German silver isn't silver at all and contains copper, zinc, and nickel.

Hope this helps!

Diffusion of Sucrose in Gelatin. A layer of gelatin in water 5 mm thick and con-taining 5.1 wt % gelatin at 293 K separates two solutions of sucrose. The concentra-tion of sucrose in the solution at one surface of the gelatin is constant at 2.0 g sucrose/100 mL solution, and 0.2 g/100 mL at the other surface. Calculate the flux of sucrose in kg sucrose/s

Answers

Answer:

the flux of sucrose is 9.072 × 10⁻⁷  kg sucrose / m² sec

Explanation:

Given the data in the question;

water-gelatin solution separating two different concentration solutions of sucrose; 5.1 wt % gelatin at 293 K; at this conditions diffusivity of sucrose in water gelatin solution is;

[tex]D_{AB}[/tex] =  0.252 × 10⁻⁹ m²/sec.

we know that; 1 L = 0.001 m³, 1mL = 0.001 L

[tex]C_{A1}[/tex] = 2.0 g sucrose/100 mL = 2.0 × 10⁻³ kg sucrose / 100 × 10 ⁻³ L

[tex]C_{A1}[/tex]  = 2.0kg sucrose / 100 L

[tex]C_{A1}[/tex] = 2.0 kg sucrose / 100 × 10⁻³ m³

[tex]C_{A1}[/tex]  =  20 kg sucrose / m³

[tex]C_{A2}[/tex] =  0.2 g sucrose/100 mL = 0.2 × 10⁻³ kg sucrose / 100 × 10⁻³ × 10⁻³ L

[tex]C_{A2}[/tex] = 2 kg sucrose / m³

Thickness ß = 5 mm = 5 × 10⁻³ m

Now, flux of sucrose in kg sucrose / m³sec will be;

using the formula, [tex]N_{A}[/tex] = [tex]D_{AB}[/tex] /ß ( [tex]C_{A1}[/tex] - [tex]C_{A2}[/tex] )

we substitute

[tex]N_{A}[/tex] = (0.252 × 10⁻⁹ m²/sec /  5 × 10⁻³ m) ( 20 kg sucrose / m³ - 2 kg sucrose / m³ )

[tex]N_{A}[/tex] = (0.252 × 10⁻⁶ / 5) × 18 kg sucrose / m² sec

[tex]N_{A}[/tex]  = 4.536 ×  10⁻⁶  / 5 kg sucrose / m² sec

[tex]N_{A}[/tex] = 9.072 × 10⁻⁷  kg sucrose / m² sec

Therefore, the flux of sucrose is 9.072 × 10⁻⁷  kg sucrose / m² sec

what causes the different crusts to rise and lower?

Answers

Answer:

tectonic plates

Explanation:

The hot mantle below the crust and its high pressure on the crusts. It also created volcanoes. The hot mantle rises then sinks back down cause if the mantle rise due to heat, then it will fall due to cooling.

Which of the following can be calculated from the mass of the reactants used in a chemical reaction? (Select all that apply)
Theoretical yield of products
Amount of limiting reactant used in a reaction
Actual yield of products
Amount of excess reactant from a reaction

Answers

Answer:

Can you explain it more please

Explanation:

5 pos. 1. An excess of sodium sulfate was added to a 500. mL sample of polluted water. The
mass of lead (II) sulfate that precipitatcd was 308.88 mg. Determine the mass of lead that was in
the polluted water.
Na2SO4(aq) + Pb2+ (aq) → 2Na(aq) + PbSO4(s)

Answers

Answer:

[tex]m_{Pb^{2+}}=0.211gPb^{2+}[/tex]

Explanation:

Hello!

In this case, according to the stoichiometry of the reaction, it is possible to evidence the 1:1 mole ratio between lead (II) ions and lead (II) sulfate precipitate; that is why we can compute the mass of lead (II) in the polluted water as shown below:

[tex]m_{Pb^{2+}}=308.88mgPbSO4*\frac{1gPbSO4}{1000mgPbSO4} *\frac{207.2gPb^{2+}}{303.26gPbSO4} \\\\m_{Pb^{2+}}=0.211gPb^{2+}[/tex]

Best regards!

What element does Ca-37 turn into when it gives off radiation?
K-37
K-39
Sc-37
Sc-45

Answers

Ca-37 decays by positron emission (beta plus decay) to form K-37.

In this type of decay, a proton is converted into a neutron, giving off a positron (an antielectron) in the process. In essence, the atomic number of the element is reduced by one. The element with the atomic number of Ca minus one is potassium (K); the mass number remains unchanged (37) since it is the sum of the protons and neutrons in the nucleus, which is the same before and after decay (a proton became a neutron, and the positron isn’t a nucleon).

a molecure that contains 3 iddentical polar bonds to the central atom will be

Answers

ANSWER:

Nonpolar

sorry if I'm wrong

On another planet, the isotopes of titanium have the given natural abundances.
Isotope Abundance
Mass (u)
46Ti
70.600%
45.95263
48Ti
12.900%
47.94795
50Ti
16.500%
49.94479
What is the average atomic mass of titanium on that planet?

Answers

im pretty sure you do the number times the percentage converted to a decimal and then add the sums so (46*0.706)+(48*0.129)+(50*0.165)
32.476+6.192+8.25
=46.918 amu

*i dont trust my calc so pleasee check if the answer is right and also remember to convert a percent to decimal move the decimal back 2 places so like for 12.9% the decimal is gonna be 0.129

hope this helpss ask if you have questions

QUESTION 7 Can you use alligation for any type of liquid? ​

Answers

Answer:

Yes you can use alligation for a type of liquid. Explanation: Alligation is an old and practical method of solving arithmetic problems related to mixtures of ingredients.

Matter are anything that is made up of atoms. The quantity of matter can be observed only on the basis of mass and volume calculation. Thus, we can use allegation for any type of liquid.

What is matter?

Matter is a substance that has some mass and can occupy some volume. The matter is mainly used in science. Matter can be solid, liquid or gas.

Matter is anything that is made up of atoms. Anything around us that can be physically seen and touched are matter. Ice, water and water vapors are example of matter.

Mass can also be represented as number of molecules. We also saw that matter occupy some volume and that volume is measured only in liter. Allegation is a form of liquid that we may utilize. Allegation is a time-tested and useful strategy for tackling mathematical issues involving combinations of elements.

Thus, we can use allegation for any type of liquid.

To learn more about matter, here:

https://brainly.com/question/4562319

#SPJ2

Convert Fahrenheit temperature
to Kelvin scales​

Answers

°C + 273.15 = K. The basic formula for converting Fahrenheit into Celsius is (°F − 32) × 5/9 = °C. To convert Fahrenheit degrees into Kelvins, (°F − 32) × 5/9 + 273.15 = K.

Answer:

K = (F – 32)5/9 + 273.15

Explanation:

You basically convert Fahrenheit to Celcius and then to Kelvin

Here's the entire formula:

K = (x °F – 32)5/9 + 273.15

Which two statements about composite materials is true?

A. They're made up of more than one substance

B. They have the same or similar properties as the materials used to make them

C. They're always made of metal

D. They're readily available in nature

help as fast as u can please​

Answers

A and D are correct

where do coal,oil and natural gas came from?​

Answers

Answer:

I hope it will help you

plz mark me as brainliest

plz thank my answer

A flask at room temperature contains exactly equal amounts (in moles) of nitrogen and xenon.

a. Which of the two gases exerts the greater partial pressure?
b. The molecules or atoms of which gas have the greater average velocity?
c. The molecules of which gas have the greater average kinetic energy?
d . If a small hole were opened in the flask, which gas effuses more quickly?

Answers

Answer:

a) Same

b) Nitrogen

c) Same

d) Nitrogen

Explanation:

a)

The formula for partial pressure of a gas is equal to

[tex]p_B = n_B \frac{RT}{V}[/tex]

Here nB is the number of moles .

The number of moles for both the gases are same and hence the partial pressure for the two gases will also be same.

b) The greater average velocity is calculated by using following formula

[tex]v_{RMS} = \sqrt{3RTM}[/tex]

Here M is the molar mass.

Molar mass of nitrogen is greater than the molar mass of xenon and hence nitrogen will have higher greater average velocity

c) As we know, the average kinetic energy of gas particles is dependent on the absolute temperature of gas and if all the gases are at same temperature, their kinetic energy will also be same. Since nitrogen and xenon are at same temperature, their kinetic energy will be same

d) Effusivity is depended directly on  the thermal conductivity,  density and  and the specific heat capacity.

All these three parameters are higher in case of nitrogen. Thus, it will effuse first

Which is correct order of the weather observed with each cloud type from 1 to 4?


A. Rain, thunderstorm, snow, fair

B. Light rain, fair, thunderstorm, fair

C. Light rain, thunderstorm, fair, fair

D. Hail, lightning, thunderstorm, fair

Answers

Answer:i thinks its A

Explanation:but who knows

PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP

DUE IN 5 MINUTES CHEMISTRY DIMENSIONAL ANALYSIS

In 2009, Usain Bolt ran 100 meters in 9.58 seconds. What is this speed in km/hr? (!! DIMENSIONAL ANALYSIS!! NOT A REGULAR PROBLEM)

Answers

100 m = 0.1 km
9.58 sec = 9.58/3600 = 0.00266 hr
Speed = 0.1/0.00266= 37.6 km/hr
Can you mark it brainliest?

How to make 0.01 Molar solution in 30 ml of water

Answers

Answer:

You see the concentration decreased ten fold, from 1 M to 0.1 M.

You can simply increase the volume by ten times.

For example

If you have 250 mL of 1 molar HCl, you can add distilled water upto 2500 mL. Now the concentration is 0.1 molar.

If you want to use the serial dilution method, you can use the C1V1=C2V2 equation.

C1 = starting concentration.

C2 = final concentration.

V is for volume.

So let's say you have 500 mL of 1 M HCl and you only want 50 mL of 0.1 M HCl.

1 M x V1 = 0.1 M x 50 mL

V1 = 5 mL

So you take 5 mL of the original (stock) solution and dilute it up to 50 mL. Then you have 50 mL of 0.1 M HCl.

Explanation:

How many molecules are there in 10.5 grams of iron (111) sulfate trihydrate? With work shown

Answers

Fe2(SO4)3.3H2O = 56*2 + 3*(32+16*4)+3*(1*2+16) = 454 g/mol
Mol =m/M = 10.5/454 = 0.023 mol
Can u mark it brainliest ?

How many atoms are in 12 moles of sodium?

Answers

Answer: There are 1.20 x 1024 atoms of sodium in 2 moles

Explanation:

A food company produces raspberry coulis as a topping for its best-selling line, double strength chocolate mousse pie. Fresh raspberries comprising 5% seeds, 20% pulp solids, and 75% water are homogenised and placed in a stainless steel vat. Sugar is added to give a raspberry:sugar mass ratio of 3.5:1. The mixture is blended, strained to remove the seeds, then heated to reduce the water content to 35%. Half a tonne of coulis is produced every day.

Required:
a. What mass of raspberries is required per week?
b. How much sugar is required per week?
c. What is the sugar content of the coulis?

Answers

Answer:

5357.1429kg per week

2142.8571 kg per week

Explanation:

Given that :

Fresh Raspberries :

5% = seeds

20% = pulp solids

75% = water

Raspberry : Sugar = 3.5 : 1

Water content = 35%

Coulis produced per day = 0.5 tonnes

Mass of Raspberry produced per week :

Mass is measured in kg;

1 tonne = 1000kg

0.5 tonne = (1000/2) kg = 500kg

Mass of Coulis produced per week = 500kg * 7 = 3500kg

Coulis contains 35% water, Raspberry required 75% water :

(3500 / 35) * 75 = 7500kg

Raspberry : Sugar ratio = 3.5 : 1

Mass of Raspberry :

[7500 - (1 /3.5) * 7500]

7500 - 2142.8571

= 5357.1429kg per week

B.

Sugar required per week:

(1/3.5) * 7500kg

= 2142.8571 kg per week

C.)

Sugar content in coulis :

What are the three types of plate boundaries? What is the direction of movement at each boundary?

Answers

There are three kinds of plate tectonic boundaries: divergent, convergent, and transform plate boundaries.

This image shows the three main types of plate boundaries: divergent, convergent, and transform.

This image shows the three main types of plate boundaries: divergent, convergent, and transform. Image courtesy of the U.S. Geological Survey. Download image (jpg, 76 KB).

The Earth’s lithosphere, which includes the crust and upper mantle, is made up of a series of pieces, or tectonic plates, that move slowly over time.

A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth’s mantle to the surface, solidifying to create new oceanic crust. The Mid-Atlantic Ridge and Pacific Ring of Fire are two examples of divergent plate boundaries.

When two plates come together, it is known as a convergent boundary. The impact of the colliding plates can cause the edges of one or both plates to buckle up into a mountain ranges or one of the plates may bend down into a deep seafloor trench. A chain of volcanoes often forms parallel to convergent plate boundaries and powerful earthquakes are common along these boundaries.

At convergent plate boundaries, oceanic crust is often forced down into the mantle where it begins to melt. Magma rises into and through the other plate, solidifying into granite, the rock that makes up the continents. Thus, at convergent boundaries, continental crust is created and oceanic crust is destroyed.

Two plates sliding past each other forms a transform plate boundary. One of the most famous transform plate boundaries occurs at the San Andreas fault zone, which extends underwater. Natural or human-made structures that cross a transform boundary are offset—split into pieces and carried in opposite directions. Rocks that line the boundary are pulverized as the plates grind along, creating a linear fault valley or undersea canyon. Earthquakes are common along these faults. In contrast to convergent and divergent boundaries, crust is cracked and broken at transform margins, but is not created or destroyed.

Beryllium oxide, Beo, is an electrical insulator. How
many moles of beryllium oxide qre in a 250 gram
sample of the compound?

Answers

Answer:

There are 10.0 moles of beryllium oxide in a 250 grams sample of the compound.

Explanation:

We can calculate the number of moles (η) of BeO as follows:

[tex] \eta = \frac{m}{M} [/tex]

Where:

m: is the mass = 250 g

M: is the molar mass = 25.0116 g/mol

Hence, the number of moles is:

[tex] \eta = \frac{250 g}{25.0116 g/mol} = 10.0 moles [/tex]

Therefore, there are 10.0 moles of beryllium oxide in a 250 grams sample of the compound.  

I hope it helps you!

if an atom has 22 protons 28 neutrons 20 electrons what would its atomic number be

Answers

Answer:

22

Explanation:

The atomic number indicates the amount of protons, so it would be 22

If each water molecule contains 2 hydrogen atoms, how many total oxygen atoms in 20 water molecules?
10
20
40
60​

Answers

the answer is 10 because if their is 20 molecules of hydrogen then their is one oxygen molecule for each which results in 20 divided by two which equals 10

Is nitric acid a strong or weak acid. Explain your answer.

Answers

Answer:

There are only a few (7) strong acids, so many people choose to memorize them. All the other acids are weak. The strong acids are hydrochloric acid, nitric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, perchloric acid, and chloric acid.

Explanation:

그것은 당신의 교육에 도움이 되기를 바랍니다

SUMMARY: Write a 3-4 sentence summary about the Periodic Table.

Answers

Answer:

The periodic table, also known as the periodic table of elements, is a tabular display of the chemical elements, which are arranged by atomic number, electron setup, and repeating chemical properties. The structure of the table shows occasional (popular things/general ways things are going). The seven rows of the table, called periods, generally have metals on the left and nonmetals on the right. The columns, called groups, contain elements with almost the same chemical behaviours. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases. Also displayed are four simple rectangular areas or blocks connected with the filling of different atomic orbitals.

Explanation:

i think that's what you're looking for...

how much energy must be released by 50.0 g of steam to decrease its temperature from 125.0 degrees Celsius to 100.0 degrees Celsius ?

Answers

Answer:

5250 Joules

Explanation:

Mass = 50g

Initial Temperature = 125.0 degrees Celsius

Final Temperature =  100 degrees Celsius

Temperature change = Final - Initial = 100 - 125 = -25

Heat = ?

These quantities are related by the equation;

H = mCΔT

where c = specific hear capacity = 4.2 J/g°C

H = 50 * 4.2 *  (-25)

H = -5250 J (The negative sign is because heat is being released)

6. Elements in column (group) 18 (8A) are called the________ and the outermost electrons are found in
the p sublevel. Color these elements a different color and reference this group on the legend.

Answers

Answer:

Noble gases

Explanation:

Noble gases have filled electron shells (group 18=8 electrons) and are all odorless, colorless, monatomic gases with very low chemical reactivity.

The reaction for luminol is basically luminol and hydrogen peroxide. In the instructions for the preparation of the chemicals, I found that the hydrogen peroxide is 44 times more concentrated than the luminol. The fact that there are two reactants, should make you wonder if the reaction is second order overall. However, in class, we presented data that showed that the natural log of the amount of light change over time was a straight line with a negative slope. This would tend to make you think that the reaction is first order, given the information here, you can confidently say that this reaction is:
A. zeroth order
B. first order
C. pseudo first order
D. second order
E. third order

Answers

Answer:

pseudo first order

Explanation:

We know that for a first order reaction, the plot of the natural log of the amount of reactant against time is a straight line with a negative slope. In this case the amount of substance is monitored using the amount of light change. Hence, the plot of the natural log of the amount of light change against time was a straight line with a negative slope.

The statement above characterizes a first order reaction. However, we must remember that the reaction is bimolecular; it involves luminol and hydrogen peroxide. The hydrogen peroxide is 44 times more concentrated than the luminol making the reaction a pseudo first order reaction.

A Pseudo first-order reaction can be defined as a second-order or bimolecular reaction that is made to behave like a first-order reaction(Byjus).

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