Which of these is an example of physical change

A) iron melting
B) steel rusting
C) paper burning
D) wood decaying ​

Answers

Answer 1

Answer:

it is A mark me big brain pls

Explanation:

Answer 2
I would say d sorry if it is wrong

Related Questions

Which gas contains the same number of molecules as 9g of water?
A) 2g of hydrogen
B) 14g of nitrogen
C) 32g of oxygen
D) 44g of carbon dioxide​

Answers

Answer:

B) 14g of nitrogen

Explanation:

To calculate number of molecules in 9g of water, we first convert mass to mole by using mole = mass/molar mass i.e.

mole = 9g/18g/mol of water

mole = 0.5mol

Next, we multiply by 6.022 × 10^23 molecules to get 3.011 × 10^23 molecules in 9g of water (H2O).

- For hydrogen gas: Molar Mass = 2g/mol, mass = 2g

mole = 2/2 = 1

No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.

- For Nitrogen gas: Molar Mass = 28g/mol, mass = 14g

mole = 14/28 = 0.5mol

No. of molecules = 0.5 × 6.022 × 10^23 = 3.011 × 10^23 molecules.

- For Oxygen gas: Molar Mass = 32g/mol, mass = 32g

mole = 32/32 = 1mol

No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.

- For carbondioxide gas: Molar Mass = 44g/mol, mass = 44g

mole = 44/44 = 1mol

No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.

Based on he results of each calculation, NITROGEN contains the same number of molecules as 9g of water

(11) su pilate
The substance which is most suitable for drying ammonia is

Answers

Answer:mark as brainliest

Explanation:H2SO4 and anhydrous calcium chloride CaCl2 are not used to dry ammonia because they react with it. The gas is passed through fresh quicklime (solid calcium oxide lumps) to effectively dry it.

In the redox reaction AgNO3 + Na → NaNO3 + Ag, which element has been
oxidized?

Answers

Answer:

sodium I think .............

Ice sheets once covered the upper northeastern portion of the United States.
True or False?

Answers

Answer:

I do believe the answer is false.

Hope This Helps!!

The composition of a compound is 6.27 g calcium and 1.46 g nitrogen.
Calculate the empirical formula.

Answers

Answer:

Ca₃N₂

Explanation:

The empirical formula is the simplest whole-number ratio between moles of each element present in a molecule.

Thus, we need to convert mass of each atom to moles and find the ratio between these as follows:

Moles N:

1.46g * (1mol / 14.0067g) = 0.104moles

Moles Ca:

6.27g * (1mol / 40.078g) = 0.156moles

The ratio between Moles N and moles of Ca is:

0.156moles / 0.104 moles = 1.5

That means there are 1.5 moles of Ca per mole of N. As empirical formula must be given in whole numbers:

There are 3 moles of Ca per 2 moles of N.

Empirical formula is:

Ca₃N₂

Options are:
1. 4
2. 8
3. 2
4. 1

Answers

Answer:

1. 4

Explanation:

there are four atoms of hydrogen. you can tell because there is a 4 after the H.

The correct answer is 4 :)

The diagram shows changes of state between solid, liquid, and gas. The atoms of a substance lose energy during a change of state. Before the change, the atoms are close together but are able to slide past one another.Which arrow represents the change of state described above?

M
N
P
Q

Answers

P - solid to liquid.

Answer:

D. P

Hope it works!

Explanation:

Any 1 help with Chemistry here??

Answers

Nope sorry bro:((((((

BEBE
Use the activity series below to predict whether the following reactions will take place.
803
F2 > Cl2 > Br2 > 12
Cl2 + 2Rbl - 2RbCI+ 12
12 + NiBr2 - Nil2 + Brz
yes
yes
no
0
no

Answers

Reaction 1 : yes

Reaction 2 : no

Further explanation

The metal activity series is expressed in voltaic series  

Li-K-Ba-Ca-Na-Mg-Al-Mn- (H2O) -Zn-Cr-Fe-Cd-Co-Ni-Sn-Pb- (H) -Cu-Hg-Ag-Pt-Au  

The more to the left, the metal is more reactive (easily release electrons) and the stronger reducing agent  

The more to the right, the metal is less reactive (harder to release electrons) and the stronger oxidizing agent

So that the metal located on the left can push the metal on the right in the redox reaction  

From activity series of Halogen :

F₂>Cl₂>Br₂>I₂

F₂ is the strongest oxidizing agent

1. Reaction

Cl₂ + 2Rbl - 2RbCI+ I₂

Cl₂>I₂⇒reaction can occur⇒yes, reactions will take place.

2. Reaction

I₂ + NiBr₂ - NI₂ + Br₂

Br₂>I₂⇒Reaction can't occur⇒no, reaction will not take place

SIMPLE ANSWERS ONLY I ALREADY GOOGLED AND DIDN'T FIND ANYTHING PLEASE ANSWER IN YOUR OWN WORDS.

How is atomic mass calculated for elements on the periodic table.

Answers

Explanation:

The atomic mass of elements on the periodic table are derived from the proportion of the geonormal abundance of the different isotopes of an element.

Using a mass spectrometer, the proportion/percentage/fraction by which each of the isotopes of an element occurs in nature is determined. This proportion is the geonormal abundance. From this the atomic mass of the element can be derived. Simply multiply the mass by the abundance and sum the values for the same isotopes together.

A chef fills a 60-ml container with 45.3 g of cooking oil. What is the density of the oil?

Answers

Answer:

0.76 g/mL

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question we have

[tex]density = \frac{45.3}{60} \\ = 0.755[/tex]

We have the final answer as

0.76 g/mL

Hope this helps you

A book is sitting on a desk. The area of contact between the book and the desk is 0.06 m2 of the body's weight is 30 N what is the pressure the book exerts on the desk

Answers

Answer:

500N/m²

Explanation:

The Pressure can be calculated using the formula:

P = F/A

Where;

F = force (N)

A = Area (m²)

Based on the information provided in the question, F = 30N, A = 0.06m²

P = F/A

P = 30/0.06

P = 500N/m²

Which of the following statements is true?

A. Cations are always larger than the atoms from which they form.
B. Cations are always the same size as the atoms from which they form.
C. Anions are always larger than the atoms from which they form.
D. Anions are always smaller than the atoms from which they form.

Answers

Answer:

B. Cations are always the same size as the atoms from which they form.

Explanation:

That's i read in the book

"Anions are larger in size than the atoms from which they form" is a true statement. Therefore, option (C) is correct.

What are anions and cations?

A cation contains more protons than electrons in it, which give it a net positive charge. A cation can be formed by losing one or more electrons must be lost by atoms.

The charge on the ion will be equal to the number of electrons lost as indicated after the chemical symbol. For example, silver (Ag) has lost one electron to become Ag⁺. The size of the cation is always smaller than the atom from which it formed.

An anion contains more electrons than protons which gives it a net negative charge. An anion can be formed by gaining one or more electrons or typically pulled away from other atoms.

The charge of the anion will be equal to the number of electrons gained, which is indicated after the chemical symbol.  For example, chlorine (Cl) accepts one electron to become Cl⁻.

The size of an anion is greater than the atoms from which it formed as the number of electrons in the ion increases and effective nuclear charge decreases.

Learn more about anions and cations, here:

https://brainly.com/question/20435320

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2. If 300.0 mL of a 2.5 M solution of nitric acid is added to 500.0 mL of water, what is the molarity of the
dilute solution?

Answers

Answer:To calculate the Molarity of a 70 wt. % Nitric Acid the number of moles of HNO 3 present in 1 liter of acid needs to be calculated. Knowing the density of the acid to be 1.413 g/mL, we can calculate the weight of 1 L of 70% HNO 3 to be 1413

Explanation:

A solution containing 15.2 g of BaBr2 is reacted with a solution containing excess Na3PO4 to form 9.50 g of precipitate. What is the percent yield of the reaction?

Answers

Answer:

Explanation:

  3BaBr₂       +       2Na₃PO₄     =       6BaBr + Ba₃(PO₄)₂ (s)

3 x 297 = 891 gm                                          1 x 602 = 602 gm

891 gram of BaBr₂ yields     602 gram of precipitate

15.2 gram of BaBr₂ yields     602 x 15.2 / 891 gram of precipitate

= 10.23 gram

actual yield = 9.5 gram

percent yield = 9.5 x 100 / 10.23

= 92.86 % .

Find the mass, in grams, of 7.50×1024 formula units of aluminum oxide.

Answers

The mass is 4.4435, I think hope this helps

How many valence electrons would be shown in the electron dot diagram of a helium atom?

Answers

Answer:2

Explanation:

The number of valence electrons for a helium atom is 2. This can be confirmed by looking at the electronic configuration.

Helium atom:

Helium is placed in the noble gas series as it has certain properties of it. The atomic number of helium is 2. Thus, it has two electrons in its outermost shell but it has completely filled orbital.

Electronic configuration of He = 1s2

Thus, for drawing the electron dot structure, there are two valence electrons.

Find more information about Helium atom here:

brainly.com/question/26226232

HELPPPP!!! I NEED IT VERY MUCHHHH

Answers

Answer:

mabye C at least if its not right sorry .

Which of the following are chemical or nuclear reactions?

1. chemical plant explosion
2. Tsar Bomba
3. meteor strike
4. Tunguska Event
5. Super Volcano eruption
6. fusion powering the sun

Answers

Answer:5) super Volcano eruption

Explanation:

Answer:

#1, #2, #4, and #6 are the answers.

Explanation:

#2, #4, and #6 have something to do with radioactivity which is mostly categorized in nuclear reactions, #3 and #5 are partly categorized in thermal reactions while a chemical plant explosion is almost categorized as a chemical bomb; Chemical explosions may be either decomposition or combination reactions. Decomposition reactions occur in materials such as trinitrotoluene (TNT) and nitroglycerine. Combination reactions require that two or more components react together exothermically to produce hot gases. Some examples are ammonium nitrate and fuel oil (ANFO), and gunpowder (potassium nitrate, carbon, and sulfur). In conclusion, #1, #2, #4 and #6 are the answers.

What type of relationship exists between
dissociation constant and pk values

A Linear
B Directly Proportional
C Direct
D Inverse

Answers

Answer: D inverse . The product of Ka and Kb equals the auto-dissociation constant for water.

Explanation: i hoped that helped and Plz give as a brainliest !!

I think the answer would be D Inverse, but I’m not 100%

A science teacher placed a magnesium wire in flame.the wire turned white where the flame touched it. which statement best explains the chemical change

A. a new substance formed

D. the magnesium wire changed shape

the subject is science

Answers

Answer:

A

Explanation:

The correct answer would be that a new substance is formed.

When magnesium wire is burnt in the presence of oxygen, the wire reacts with oxygen and a new substance known as magnesium oxide is formed. The new substance is usually white in color and the equation of the reaction is as below:

[tex]2 Mg (s) + O_2 (g) --> 2 MgO (s)[/tex] (white)

Hence, the correct option is A.

Answer:

Explanation:A new substance formed. Promise.

IMMA WAIT FOR MY BABY EVEN IF IT TAKES ALL NIGHT !!!!!!

Answers

Answer:

um okay lol

Explanation:

Answer:

Oh ok

Explanation:

Also can u pls mark me brainliest im new pls

Study the image.

A world map showing the Principal World Air Masses. The four major types of air masses are noted on the map.

Which air mass has formed immediately north of Antarctica in the image?

Answers

Answer:

a

Explanation:

A world map showing the Principal World Air Masses. The four major types of air masses are noted on the map. The maritime polar has formed immediately north of Antarctica in the image.

Where is the maritime polar formed?

The north Pacific Ocean produces the majority of the maritime polar air masses that affect the United States. However, maritime polar air occasionally forms in the North Atlantic Ocean and moves into the New England states.

In the winter, for example, an arctic air mass can move over the ocean, picking up some warmth and moisture from the warmer ocean and transforming into a maritime polar air mass (mP), which is still fairly cold but contains moisture.

In the image, the maritime polar has formed immediately north of Antarctica. The temperature of mP air varies between just above freezing and below 70 degrees Fahrenheit. As it moves over elevated terrain, mP air changes. Mountain ranges on the windward side

Thus, The maritime polar has formed immediately north of Antarctica in the image.

To learn more about the maritime polar, follow the link;

https://brainly.com/question/7423218

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Why don't we use the plutonium (Pu) from reprocessed/used nuclear fuel? There are 2 correct answers. (this is for my earth science, it's an edpuzzel)

Answers

Answer:

Erosion, and soil damage

Explanation:

We do not use the plutonium (Pu) from reprocessed / used nuclear fuel because Plutonium has high rate of spontaneous fission and Uranium is the main fuel which is used for nuclear reactor.

What is Nuclear reactor ?

A nuclear reactor is a device which is used to initiate and control a chain reaction to release large amount of steady heat there by produces energy.

Thus from above conclusion we can say that We do not use the plutonium (Pu) from reprocessed / used nuclear fuel because (i) Plutonium has high rate of spontaneous fission and (ii) Uranium is the main fuel which is used for nuclear reactor.

Learn more about the Nuclear reactor here: https://brainly.com/question/23160065
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Express in scientific notation. Choose the answer with the proper number of significant figures.
9x109
4.5 x 10

Answers

Answer:

4.5 times 10 = 45

Explanation:

"Non-zero digits are always significant. Any zeros between two significant digits are significant. A final zero or trailing zeros in the decimal portion ONLY are significant."

Arrange the following atoms in order of increasing ionization energy: lithium, oxygen, magnesium, strontium, chlorine, and tellurium. Explain your order.

Answers

Answer: lithium < strontium < magnesium < tellurium < chlorine < oxygen  

Explanation:

Ionization energy is the energy required to remove the most loosely bound electron from an isolated gaseous atom.

In a period, the ionization energy increases as we move across a period as the size decreases. The electrons get added to the same shell and the nuclear charge increases.The valence shell moves nearer to the nucleus.  Thus more energy is required to remove the valence electron.

In a group , the ionization energy decreases from top to bottom as we move down a group. The size increases as the electrons get added up in the new shell, the electron in the outermost orbital gets far away from the nucleus. And hence, the electron will be easier to remove. Thus, lesser energy is required to remove the valence electron.

The correct order of increasing ionization energy will be:

lithium < strontium < magnesium < tellurium < chlorine < oxygen  

Ionization energy is the energy required to remove the most loosely bound electron from the last shell.

In the periodic table, there are groups and periods.

Group represents the vertical column.The period represents the horizontal rows.

In a period, the ionization energy increases as we move across a period as the size decreases. The electrons get added to the same shell and the nuclear charge increases.

The valence shell moves nearer to the nucleus.  Thus more energy is required to remove the valence electron.

In a group, the ionization energy decreases from top to bottom as we move down a group.

The size increases as the electrons get added up in the new shell, the electron in the outermost orbital gets far away from the nucleus. And hence, the electron will be easier to remove. Thus, lesser energy is required to remove the valence electron.

The correct order of increasing ionization energy is:

lithium < strontium < magnesium < tellurium < chlorine < oxygen

For more information, refer to the link:-

https://brainly.com/question/1602374

Match the definitions on the left with the terms on the right.

Answers

Answer:what defino? I don’t see nun

Explanation:

Answer:

answer in picture

Explanation:

I don’t really have a question... and my teacher says I need to give one related to this reading above :/

Can somebody plz give one that makes sense (WILL MARK BRAINLIEST)

Answers

Answer:

Just say I wonder why teachers give homework :/

Explanation:

can someone solve c and d? ​

Answers

Answer:

Na + + e - → Na.

Pb 2+ + 2e - → Pb.

2H + + 2e - → H 2

Explanation:

How many valence electrons are found in atoms of group 14?

Answers

Answer:

4 valence electrons.

Explanation:

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