Obi is trying to determine if a powdery, solid substance is an element or a compound. After recording some observations, he strongly heats a sample of the solid over a burner flame. After fifteen minutes, he turns off the flame and allows the sample to cool. He records his final observations in the data table.

Which is the best explanation of his results?

The heating changed some of the sample to gas, causing the mass to decrease without breaking down the sample. Therefore, the original sample is a compound.
The appearance stayed the same, showing that the sample was not broken down by heating. Therefore, the original substance is an element.
The mass decreased during heating and some of the impurities escaped. Therefore, the original substance is an element.
The chemical reaction with acid changed, showing that the sample was broken down by heating. Therefore, the original substance is a compound

Obi Is Trying To Determine If A Powdery, Solid Substance Is An Element Or A Compound. After Recording

Answers

Answer 1

Answer: I am thinking C maybe.

Explanation: I don't if this is right but I think it is C.

Answer 2

Answer:

D

Explanation:

Took the test on edge...


Related Questions

All 6 sides of a cube measure 65mm. Calculate the volume of the cube in cm32

Answers

Same I need help also

What is a scale and why do you use it?

Answers

To calculate the weight of something. It is used to find the weight of an object

Answer:

Scale is defined as a system or series of marks used for measuring or registering. An example of scale is what someone would use to figure out the length of something. An example of scale is what someone would use to find out how much they weigh.

Explanation:

A force is always a push. true or false ?

Answers

True because ur using the force to push

What is the importance of protons ?

Answers

Protons are important because they help keep the nucleus together, they also attract negatively charged electrons and keep them in orbit around the nucleus.

The protons inside a atoms nucleus help to bind the nucleus together. They attract the negative charged electrons and keep them in orbit around the nucleus. The number of protons in an atoms nucleus determine which chemical element it is

A black hole is a
a. an object of zero volume and infinite density
b. an object from which nothing, not even light, can escape
c. an object that emits x rays as matter falls into it
d. an object that disappears from our universe
e. all of the above

Answers

Answer:

B. an object from which nothing, not even light, can escape

Explanation:

Where does the heat that is needed to warm the surface of the ocean come from? A. the Sun B. the Earth's interior C. animals D. the Earth's surface

Answers

Answer:

A. The Sun

Explanation:

Answer:

A

Explanation:

Most of our heat source on Earth comes from the Sun.

which element has an atom with the following composition? 24 protons, 28 neutrons and 24 electrons.

Answers

Chromium - 28

The amount of protons is equal to the atomic number and this can always be used to identify the element

Please help me with this question after I have help with my questions i will be giving away 50 points to 4 people to keep on the look out on my page xxx

Answers

Answer:

I swear I would help if I knew what the hell was going on on that picture XD

Answer:

D

Explanation:

factors like heat on mcls work on a bell curve, meaning they peak and go down

Given the standard heats of reaction

Reaction ∆H 0

M(s) + 2 X2(g) → MX4(g) −98.7 kJ/mol

X2(g) → 2 X(g) +327.3 kJ/mol

M(g) → M(s) −20.1 kJ/mol


calculate the average bond energy for a single

M-X bond.

Answer in units of kJ/mol.

Answers

Answer:

Explanation:

M(s) → M (g ) + 20.1 kJ --- ( 1 )

X₂ ( g ) → 2X (g ) + 327.3 kJ ---- ( 2 )

M( s) + 2 X₂(g) → M X₄ (g ) - 98.7 kJ ----- ( 3 )

( 3 ) - 2 x ( 2 ) - ( 1 )

M( s) + 2 X₂(g) - 2 X₂ ( g ) - M(s)  → M X₄ (g ) - 98.7 kJ -  2 [ 2X (g ) + 327.3 kJ ] - M (g ) - 20.1 kJ

0 = M X₄ (g ) - 4 X (g ) - M (g ) - 773.4 kJ

4 X (g ) +  M (g ) =  M X₄ (g ) - 773.4kJ

heat of formation of M X₄ (g ) is - 773.4 kJ

Bond energy of one M - X bond =  773.4 / 4 =  193.4 kJ / mole

All covalent compounds donot exist as giant aggregates. Why?​

Answers

This is because of the attractive forces between the molecules with the absence of overall electric charge. Covalent compounds are usually gaseous molecules at room temperature and pressure.

calculate the oxidation number of s in S2O8^2-​

Answers

Given problem:

    S₂O₈²⁻

Find the oxidation number of S;

Oxidation number presents the extent of oxidation of each atom of elements a molecular formular or formula unit or an ionic radical.

  For radicals:

          "the algebraic sum of all the oxidation numbers of all atoms in an ion containing more than one kind of atom is equal to the charge on the ion  "

 S₂O₈²⁻;   oxidation number of O is usually -2

             2(S) + 8(-2) = -2

               2S - 16  = -2

               2S = -2 + 16

                2S  = 14

                   S  = +7

The oxidation state of S in the radical is +7

in your own words describe the process of a physical change​

Answers

Answer:

A physical change is when the form of an object changes, but the substance stays the same.

Example: Ice melting into water.

What are the seven most abundant elements?

Answers

Answer:

the seven most abundant elements are

oxygen

carbon

hydrogen

nitrogen

calcium

phosphorus

Explanation:

hope this helps

good luck:)

Answer:

oxygen

carbon

hydrogen

nitrogen

calcium

phosphorus

Heat rising in a hot-air balloon is an example of __________. conduction convection radiation solar

Answers

Answer:Condensation

Explanation:

it

Answer:

convection

Explanation:

I took test I got 100%

what are 2 physical changes in the carbon cycle?

Answers

Answer:

Today, the carbon cycle is changing. humans are moving more carbon into the atmosphere from other part of the earth system. more carbon is moving to the atmosphere where fossil fuels, like coal and oil, are burned.more carbon is moving to the atmosphere as you may get rid of forest by burning the tree

Explanation:

hope this give you a hint

How is iodine 131 similar to a normal atom of iodine?

Answers

Answer: Iodine 131 is a radioisotope with a very short half-life of 8.02 days, making it highly radioactive.

Explanation:

PLEASE HELP WILL GIVE BRAINLIEST​

Answers

It’s the atomic number.

The equation, reactants
product + thermal energy, describes a(n)_____
reaction.

Answers

Answer: Here you go

Explanation:

The general equation for an exothermic reaction is: Reactants → Products + Energy.

PLEASE HELP ME!!
Water (H2O) is composed of the same elements as hydrogen peroxide (H2O2).

Why do these substances have different properties?


The molecules are the same.


Water has more atoms than hydrogen peroxide.


The atoms are arranged differently in each molecule.


The atoms are the same.

Answers

Answer:

The molecules are the same.

Explanation:

Is sulfur dioxide a element?

Answers

yes it is a element.

A chemist burns 0.8 g of iron in oxygen.
The iron reacts to form 1.1 g of iron oxide.
Calculate the mass of oxygen that reacted with the iron.

Answers

Answer:

0.3g

Explanation:

1.1 - 0.8 = 0.3

Hope this helps

The mass of oxygen that reacted with the iron is 0.3g

The chemist burns 0.8g of iron in oxygen

the iron reacts to form 1.1g of iron oxide

Therefore the mass of oxygen can be calculated by subtracting the mass of iron in oxygen from the mass of iron

= 1.1 - 0.8

= 0.3g

Hence the mass of oxygen that reacted with the iron is 0.3g

Please see the link below for more information

https://brainly.com/question/9631250?referrer=searchResults

Explain what happens if you change the number of protons in an element?

Plzzz helpppp!!!​

Answers

Answer:

When you change the number of protons in an atom, you will change the atom from one element to a different element. Sometimes, when you add a proton to an element, the element will become radioactive. If you change the number of electrons in an atom, you will get an ion of the element.

What is the process called when the moon bagins to fade from full moon to new moon

Answers

Waining there’s not much to explain here it’s simple moon phases

During which process of the water cycle does water change from gas to liquid

Answers

Answer is condensation hope this help you

the amount of space an object occupies is called its

Answers

Volume is the amount of space occupied in a object

Flowering plants are the most successful group of land plants. This is due, in part, to the trait that could be the label for point C. in the cladogram. Consider the organization of the cladogram. What trait, besides flowers, is unique to this group of plants?

Answers

Answer:

seeds are protected in fruits in such kind of plants.

Explanation:

The flowering plants are also known as Angiospermae, or Magnoliophyta. Flowering plants are plants that grow flowers. Such plants use seeds to reproduce, or make more plants like them.

Seeds are protected in fruits in such kinds of plants.

Examples of flowering plants are daisies, tulips, oaks, apples.

Answer:

Seeds are protected by a fruit

Explanation:

Is the equation C2H4 —> 2C + 2H2 + 52.3 exothermic or endothermic?

Answers

Answer:

Exothermic

Explanation:

A train travels at an average speed of 25 miles per hour. How long does it take the train to travel 2000 miles?

Answers

nevermind. I was wrong. I didn't see the other answers

Which of the following has the smallest radius?

A. Br-

B. Br

C. I-

D. I

Answers

B) Br

..................

I’m pretty sure it’s Br

This chart shows characteristics of three different types of atoms.

A 3-column table with one row titled valence electrons in three types of atoms. The first column labeled Atom X has entry 6 valence electrons. The second column labeled Atom Y has entry 2 valence electrons. The third column labeled Atom Z has entry 8 valence electrons.
Which statement is best supported by the information in the chart?

Atom X will donate electrons to Atom Y.
Atom X will accept electrons from Atom Y.
Atom Y will accept electrons from Atom Z.
Atom Z will donate electrons to Atom X.

Answers

Atom X will accept electrons from Atom Y.

Answer:

B) Atom X will accept electrons from Atom Y.

Explanation:

because X has 6 electrons and Y has 2 it would make sense for Y to give to X

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