Ethan is observing chemical and physical properties of a substance. He heats a
substance and observes that the substance turns from a brown solid to a black
powder. He refers to several chemistry journals that claim this represents a chemical
reaction. From his observation and research, he concludes that the substance goes
through a chemical change when heated. How can Ethan best defend his conclusion?
A. by demonstrating that the substance will eventually melt if the temperature
continues to increase
B. by verifying that the substance is now made up of different molecules than
before it was heated
C. by verifying that the substance is made up of only one type of element
D. by demonstrating that the substance is less dense after it is heated

Answers

Answer 1

Answer:

the answer is b beacuse the substance changed


Related Questions

You have an electrolyte that dissociates completely and conducts electricity well. What type of electrolyte would it be classified as?

Answers

Answer:

Strong Electrolyte

Explanation:

Electrolytes are classified into strong and weak electrolytes. Strong electrolytes are electrolytes that completely dissociate in an aqueous solution and are as well good conductors of electricity while weak electrolytes are those that are not completely dissociated in an aqueous solution and are not very good conductors of electricity.

Examples of strong electrolytes are strong acid, strong base, and salts. Examples of weak Electrolyte are weak acids and weak bases.

Thus the correct answer is strong electrolytes.

Once a product is ready to be sold, engineers must explain their ideas to people who will bring the product to consumers.
Please select the best answer from the choices provided
ОТ
OF

Answers

Answer:

ot

Explanation:

there is no choices

Answer:

Advertise

Explanation:

once a product is ready to be sold, engineers explain their ideas to marketing people, who will advertise the product.

✓ What kind of carbon storages would be the least affected by humans?

Answers

Answer:

trio

Explanation:

What are the characteristic property's of metals such as malleability and high conductivity are due to ?

Answers

Answer:

Metallic Bonding

Explanation:

Conductivity occurs when electrons or ions are free moving. The conductivity in metals is due to electrons being delocalized in a sea of electrons. Metals contain metallic bonding which allows the electrons to freely move.

Malleability happens when adjacent layers of positive ions move relative to one another while being in contact with the sea of electrons from the metallic bonding.

What is the molar mass of H2CO3

Answers

Answer:

Molar mass of H2CO3 : 62.03 g/mol

62.03 g/mol is the molar mas of H2CO3

2) Silk is a kind of ....... fibre
a) semisynthetic b) synthetic c) Animal d) Vegetable​

Answers

*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆

Answer: Animal fibre

I hope this helped!

<!> Brainliest is appreciated! <!>

- Zack Slocum

*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆

Answer:  c) Animal

Explanation:  It is a protein based fibre so classified as animal fibre.  Vegetable fibers are cellulose based.

you may not want to wear a black shirt in the hot summer because light is

Answers

Answer:

The outer layer of fabric does get hotter because the black color absorbs more heat. And that heat doesn't get transmitted to the skin because of the thick fabric. But thin black clothing transmits that heat to the skin, making a person hotter.

Explanation:

Which of the following ions will form the weakest bond with Na+?
Br^-
F^-
CI^-
I^-

Answers

Answer:

Iodide ion, I- will form the weakest bond with sodium ion, Na+

Explanation:

Electronegativity is the ability with which a neutral atom attracts electrons to itself.

The electronegativity of the halogens decrease on going down the group among the halogens. This is is because on going down the group, the atomic size as well as ionic size of the atoms in the group increases. This increase decreases the effect of the attraction of the positive nucleus on the electrons. Thus, valence electrons can be more readily removed.

The transfer of electrons from metallic sodiummto a halogen results in annionic bond between the two atoms. The strength of the ionic bond decreases on going down the group due to decrease in electronegativity. Thus, iodide ion, I-, which is the least electronegative among the given options will form the weakest bond with Na+.

Identify the decay mode
Please answer asap no explanation needed
(Look at picture)

Answers

Answer:

1921 :3 espero y te ayude crack


A reaction in the laboratory yields 5.98 g KAI(SO2)2, How many moles of potassium aluminum
sulfate were produced?

Answers

Answer:

0.0308 mol

Explanation:

In order to convert from grams of any given substance to moles, we need to use its molar mass:

Molar mass of KAI(SO₂)₂ = MM of K + MM of Al + (MM of S + 2*MM of O)*2Molar mass of KAI(SO₂)₂ = 194 g/mol

Now we calculate the number of moles of KAI(SO₂)₂ contained in 5.98 g:

5.98 g ÷ 194 g/mol = 0.0308 mol

What has caused air quality in United States to improve/get better since the 1950s?

Answers

Answer:

better mileage on cars, took lead out of paint, smaller packaging like for delivery and store products, EPA laws updating

Answer:

Reducing pollution from transportation sources has led to healthier air for Americans. In cities, smog has been visibly reduced.

Explanation:

i hope this helped

Find the kinetic energy of the horse using KE=1/2 mv².
A 500-kilogram horse runs at 5 meters/second. The horse’s kinetic energy is
[blank] joules.

Answers

KE=6,250Joules
You plug in your given numbers and remember to square 5 because that’s the speed

Answer:

6250

Explanation:

so m=500 and v=5

so v²=25

using the equation we can do 1/2 x 500 x 25 = 6250

Initially a NaOH solution was standardized by titration with a sample of potassium hydrogen phthalate, KHC8H4O4, a monoprotic acid often used as a primary standard. A sample of pure KHC8H4O4 weighing 1.518 grams was dissolved in water and titrated with the NaOH solution. To reach the equivalence point, 26.90 milliliters of base was required. Calculate the molarity o

Answers

Answer:

0.2763M NaOH

Explanation:

Based on the reaction of hydrogen phtalate, KHP, with sodium hydroxide, NaOH:

KHP + NaOH → KNaP + H₂O

1 mole of KHP reacts per mole of NaOH.

In the equivalence point, the moles of NaOH added = Moles of KHP that were dissolved.

Thus, to solve this question, we must find the moles of KHP = Moles NaOH. With the moles and the volume of NaOH required to reach the equivalence point we can find molarity of NaOH solution:

Moles KHP = Moles NaOH (Molar mass KHP = 204.22g/mol):

1.518g * (1mol / 204.22g) = 7.433x10⁻³ moles NaOH

In 26.90mL = 0.0269L:

7.433x10⁻³ moles NaOH / 0.02690L

0.2763M NaOH

Which statement describes the Arrhenius interpretation of acids and bases?
It has a wider range of applications than the Bronsted-Lowry interpretation.
It has a wider range of applications than the Lewis and Bronsted-Lowry interpretations.
It is used in situations that involve bases that do not produce hydroxide ions.
It is limited to situations that involve aqueous solutions or specific compounds.

Answers

Answer: Composition is an orderly arrangement of visual structures (elements and principles) to create a mood, add meaning and direct the viewers' attention to the purpose of the artwork. Compositions are said to be 'designed' according to the specific intent of the artist.

The statement that describes the Arrhenius interpretation of acids and bases is that it is limited to situations that involve aqueous solutions or specific compounds. Therefore, option D is correct.

What is Arrhenius's interpretation?

Arrhenius's interpretation defined an acid as a substance that increases the concentration of hydrogen ions (H⁺) when dissolved in water and a base as a substance that increases the concentration of hydroxide ions (OH⁻) when dissolved in water.

According to Arrhenius's interpretation, when an acid is dissolved in water, it releases H⁺ ions, which then react with water molecules to form H₃O⁺ ions, also known as hydronium ions.

Similarly, when a base is dissolved in water, it releases OH⁻ ions, which then react with water molecules to form H₂O molecules and more OH⁻ ions. Thus, option D is correct.

Learn more about Arrhenius, here:

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arrange the following atoms na, ca, a1, b, br, f in order of increasing electronegativity?

Answers

Explanation:

f, br, b, A1, CA, na in order of increasing electronegativity

De una misma estación salen, en el mismo instante, dos trenes, con velocidades constantes de 72 y 90 [km/h]. ¿Qué distancia separa ambos trenes luego de 2 horas de viaje si se mueven en la misma dirección ... a) ... Y en el mismo sentido de circulación?

Answers

Answer:

144 km y 180 km respectivamente.

Explanation:

¡Hola!

En este caso, dado que tenemos dos trenes con velocidades diferentes, es posible multiplicar la velocidad de cada tren por el tiempo común, con el fin the hallar la distance recorrida; es de entender, que a mayor velocidad, mayor distance ha de recorrer el tren:

[tex]d_1=72km/h*2h=144km\\\\d_2=90km/h*2h=180km[/tex]

Así, entendemos que el tren número 1 recorre 144 kilómetros, mientras que el tren número 2, 180 kilómetros.

¡Saludos!

Cool air over warm water will:
Increase in temperature
Stay the same in temperature
Decrease in temperature

Answers

Answer:

Air and Water Temperature Increases

An increase in the air temperature will cause water temperatures to increase as well. ... Lower levels of dissolved oxygen due to the inverse relationship that exists between dissolved oxygen and temperature. As the temperature of the water increases, dissolved oxygen levels decrease.

when high pressure is applied to a gas, its​

Answers

Answer: volume decreases

10 The graph below compares the density, in grams per cubic centimeter (g/cm'), of
four different substances.
DENSITY OF SUBSTANCES
20
15
Density (g/cm)
10
5.
0
w
Y
Z
Substances
Based on information from the graph, which of the following best compares the
physical properties of two of the substances?
F. Substance X has less mass than substance Y has.
G. Substance W has less volume than substance X has.
H. Substance Y would have less mass than substance Z would have if they had the
same volume.
1. Substance Z would have less mass than substance W would have if they had the
same volume.

Answers

Answer: the awnser is A

Explanation:

Edge 2020

How does the strength of a metallic bond compared to other types of bonds?

a. metallic bonds are weaker than ionic bonds or covalent bonds.

b. metallic bonds are equal in strength to ionic and covalent bonds.

c. metallic bonds are weaker than ionic bonds but stronger than covalent bonds.

d. metallic bonds are weaker than covenant bonds but stronger than ionic bonds.​

Answers

While metallic bonds have the strong electrostatic force of attractions between the cation or atoms and the delocalized electrons in the geometrical arrangement of the two metals. ... Metallic bonds are malleable and ductile, while covalent bonds and ionic bonds non-malleable and non-ductile.

The metallic bond is somewhat weaker than the ionic and covalent bond. Ionic bonds are strong electrostatic attraction forces formed between positive and negative ions. This bond is non-directional, meaning that the pull of the electrons does not favor one atom over another.

As the water is heated, the volume of
the balloon___.
Decreases
increases
remains constant

Answers

The answer would be B: increases

Hope this helps! :)✨

As the water is heated, pressure increases and hence the volume of the balloon increases.

What is pressure?

Pressure is defined as the force applied on an object perpendicular to it's surface per unit area over which it is distributed.Gauge pressure is a pressure which is related with the ambient pressure.

There are various units by which pressure is expressed most of which are derived units which are obtained from unit of force divided by unit of area . The SI unit of pressure is pascal .

It is a scalar quantity which is related to the vector area element with a normal force acting on it.It is distributed over solid boundaries and across arbitary sections of fluid normal to the boundaries at every point.Pressure is inversely proportional to volume as per Boyle's law.

Learn more about pressure,here:

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What does corona mean?

Answers

Answer:

.

Explanation:

A certain gas has a volume of 500.0 mL at 77.0°C and 600KPa. Calculate the temperature if the volume decreased to 400.0 mL and the pressure is increased to 760Kpa and assume the number of moles does not change.

Answers

Answer:

354.67K

Explanation:

Applying

P₁V₁/T₁ = P₂V₂/T₂................. Equation 1

Where Where P₁ = initial pressure, T₁ = Initial temperature, V₁ = Initial Volume, P₂ = Final pressure, V₂ = Final Volume, T₂ = Final Temperature.

From the question, we are ask to look for the final temperature,

Therefore we make T₂ the subject of the equation

T₂ = P₂V₂T₁/P₁V₁............. Equation 2

Given: P₁ = 600 kPa, V₁ = 500 mL, T₁ = 77 °C = (273+77) = 350 K, P₂ = 760 kPa, V₂ = 400.0 mL

Substitute these values into equation 2

T₂ = (760×400×350)/(600×500)

T₂ = 354.67 K

a 5 g ice cube starts life at -1 C if 2182.5 j are added to it what will be the final temperature upon his demise ?

Answers

Answer:

Final Temp = 23.92°C

Explanation:

ΔH(total) = (m·c·ΔT)ice + (m·ΔH(f))melt'g + (m·c·ΔT)water

2182.5j = (5g)(2.092j/g·°C)(1°C) + (5g)(334.56j/g) + (5g)(4.184j/g·°C)(ΔT)

(2182.5 - 10.46 - 1672.8)j = 20.92j/°C·ΔT

ΔT = (2182.5 - 10.46 - 1672.8)j / 20.92j/°C = 23.92°C

Since the melting ice starts and ends at 0°C and is then warmed to 23.92°C then the temperature change is also the final temp of the water based upon given energy input values.

10 POINTS

What is used to measure the volume of a solid with an irregular shape? O A. Gas displacement O B. Liquid displacement O C. Plasma displacement O D. Solid displacement​

Answers

Answer:

Because many objects are not regularly shaped their volume cannot be determined using a volume formula. The volume of these objects can be found by water displacement. A volume of water sufficient to cover the object is placed in a graduated cylinder and the volume read. The object is added to the cylinder and the volume read again. The difference between the two volumes is the volume of the object. This method is demonstrated using the same battery used above.

Explanation:

2 Al + Fe2O3 = Al2O3 + 2 Fe

If 0.915 mol Al2O3 is produced, how many grams of iron is produced?

Answers

Answer:

−7.389056fo3+5.436564f

−l2o3+2l

Explanation:

2al+f(2.7182822)o3=al2o3+2f(2.718282)

Step 1: Add -al^2o^3 to both sides.

7.389056fo3+2al+−al2o3=al2o3+5.436564f+−al2o3

−al2o3+7.389056fo3+2al=5.436564f

Step 2: Add -7.389056fo^3 to both sides.

−al2o3+7.389056fo3+2al+−7.389056fo3=5.436564f+−7.389056fo3

−al2o3+0fo3+2al=−7.389056fo3+5.436564f

Step 3: Factor out variable a.

a(−l2o3+2l)=−7.389056fo3+5.436564f

Step 4: Divide both sides by -l^2o^3+2l.

a(−l2o3+2l)

−l2o3+2l

=

−7.389056fo3+5.436564f

−l2o3+2l

a=

−7.389056fo3+5.436564f

−l2o3+2l

Question 10 of 10
After a person eats a sugary snack, his blood sugar levels may rise for a short
period of time. However, the body works quickly to return blood sugar levels
to normal. What is this an example of?
O A. Respiration
B. Homeostasis
C Ethics
D. Development​

Answers

B. homeostasis
Explanation: Homeostasis is any self-regulating process by which an organism tends to maintain stability while adjusting to conditions that are best for its survival.

Please answer quickly!! 1. Which of the following statements is true?
a. The breaking of bonds is exothermic, and therefore has a negative delta H value.
b. The breaking of bonds is exothermic, and therefore has a positive Delta H value.
6. The breaking of bonds is endothermic, and therefore has a negative Delta H value.
d. The breaking of bonds is endothermic, and therefore has a positive Delta H value

Answers

Answer:

d

Explanation:

a positive change in enthalpy is required to break a bond, while a negative change in enthalpy is accompanied by the formation of a bond. Bond breaking in endothermic because it requires energy, therefore delta H is positive.

chemistry:

plz help me:D

Answers

Answer:

1 atom only with the unit u.

Explanation:

The formula mass of a substance is defined as the sum of the atomic masses of all atoms in a formula unit of the particular substance in question.

Thus the correct answer is option A

Chemistry test!!! no fake answers please and if you can explain then do it because I need all the help I can get!

Answers

Answer:

(−ΔH°1)+12(−ΔH°2)+(ΔH°3)+(ΔH°4)

I hope this helps you out!! :)

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