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It is difficult to classify dissolving as physical or chemical change because at some point dissolving produce new substance which can not be reversed while at some point no new substances are produced but and the process is reversed.

Physical change is a change in which no new substance is formed and the process is easily reversible. For example, the dissolution of salt in water is a physical change since we can reverse the process to obtain salt and water.

Water + Salt <=> Salt Solution

Chemical change is a change in which new substance is formed and and the process is not reversible. For example, the dissolution of metal in acid is a chemical change since we can not reverse the process to obtain the metal.

Acid + metal —> Salt + hydrogen gas

2Na + 2HCl —> 2NaCl + H₂

Thus, we can see that it is difficult to classify dissolving as a physical or a chemical change.

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Answer:

The nucleus consists of 9 protons and 10 neutrons.  Nine electrons occupy available electron shells.

It is due to low volume of electron that causes large distance between two electrons.

When the added electron goes to smaller quantum level, the repulsive force between two electrons is less because the electron which is added occupies small space due to less volume so there is a large distance between two electrons that leads to less force of repulsion.

If the electron has more volume so it occupies more space and there will more repulsive force between two electrons so that's why we can say that the smaller volume of electron is the reason of less repulsive force.

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Answer:

the right answer is 9110

hi <3

the correct option would be all of the above

hope this helps :)

Answer:

The total number of protons and neutrons in the nucleus of an atom is called mass number.

Answer:

mass number also called nucleon number and it's the total number of neutron and proton in an atomic nucleus.

nước tự nhiên là chất đó bạn

1)proton number

2)neutron

3)(Z)

4)mass

Answer:

The answer is the 4th one

The statement about metals and nonmetals that is correct is: "The  Metals can be hammered into thin sheets, and nonmetals are brittle."

Metals are found mostly towards the left hand side of the periodic table. Non-metal character increases as you move towards the right hand side of the table.

One common property of metals is that they are malleable; this means that they can be hammered into sheets while a common property of nonmetals is that most of them are brittle.

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Answer:

16) Celsius degree and Kelvin are related since they are measuring unit of temperature.

(17) Balance and Mass are related since mass can be measured with balance.

18) Liter and cubic centimeters are related since they are used to measure capacity or volume of liquid.

19) time and second are related since time is measured in second

20) decimeter and kilometer are related since they are measuring unit of distance or displacement.

Explanation:

The two terms in each group that are related are Celsius and Kelvin, balance and mass, liter and cubic centimeter, time and second, and decimeters and kilometers.

Celsius and Kelvin are the units and they are related to each other because both of them can be used to determine or to define the temperature of the environment for anything which is needed to be measured.

The balance and mass are related to the balancing of mass and kilogram with centimeter cubic are related for density and time and second is related to each other last decimeters and kilometers unit of lengths.

Therefore, two terms in each group that are related are Celsius and Kelvin, balance and mass, liter and cubic centimeter, time and second, and decimeters and kilometers.

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Answer:

A substance made up of two different elements (hydrogen and oxygen)

Answer:

perform multiple trials for each release height instead of just one

Explanation:

Answer:

13.6g/L

Explanation:

The formula for density is D=m/V

D = Density in grams per liter (g/L)

m = Mass of sample in grams

V = volume of sample in liters

Convert 205mL to Liters as follows:

205mL (1L/1000mL) =0.205L

then simply plug into the equation for density:

2790g/0.205L = D= 13.6g/L

i found this. there's more coming up

Option A is correct way of representation of electronic configuration.

Answer:

it is a compound made up of molecules

Answer:

Isotopes have same atomic numbers, no. of protons and no. of electrons. Only their no. of neutrons and atomic mass are changed.

Na - 24:

Atomic Mass = 24

Atomic No. = 11

Hence,

No. of protons in Na-24 = 11

No. of neutrons = Atomic Mass - Atomic Number

No. of neutrons = 24 - 11

No. of neutrons = 13

Atomic Number = 11

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Answer:

[tex]\boxed {\boxed {\sf 76.1 \ g/mol}}[/tex]

Explanation:

We are asked to find the molar mass of C₃H₈O₂.

The molar mass is the mass of 1 mole of a substance. The values are found on the Periodic Table because they are equivalent to the atomic masses. However, the units are grams per mole instead of atomic mass units.

Look up the molar masses of the individual elements in the compound: carbon, hydrogen, and oxygen.

Look at the subscripts in the formula. There is a subscript of 3 after C, another of 8 after H, and another of 2 after O. Therefore, there are 3 moles of carbon, 8 moles of hydrogen, and 2 moles of oxygen in every mole of the compound. Multiply the element's molar mass by the subscript.

[tex]36.033 + 8.064 + 31.998 = 76.095 \ g/mol[/tex]

Round to the 3 significant figures. For the number we calculated, that is the tenths place. The 9 in the hundredth place to the right tells us to round the 0 up to a 1.

[tex]76.1 \ g/mol[/tex]

The molar mass of  C₃H₈O₂ is approximately 76.1 grams per mole.

Note:-

Approximate Values taken for Atomic masses

Solution:-

[tex]\\ \rm\longmapsto C_3H_8O_2[/tex]

[tex]\\ \rm\longmapsto 3(12u)+8(1u)+2(16u)[/tex]

[tex]\\ \rm\longmapsto 36u+8u+32u[/tex]

[tex]\\ \rm\longmapsto 44u+32u[/tex]

[tex]\\ \rm\longmapsto 76u[/tex]

[tex]\\ \rm\longmapsto \approx76g/mol[/tex]

Answer:

The s orbital is lower in energy than the p orbital  

Explanation:

S-orbital electrons are simultaneously closer to the nucleus (more stable) and farther from the nucleus (less stable) compared to the corresponding p-orbitals. This makes them favorable to occupy when no p-electrons are present, but less favorable to occupy when p-electrons are present, which is why they are filled first but ionize first.

Answer:

Explanation:

positive and negative

Answer:

B. Physical process is the way distillation can be separated.

Answer:

Magnesium reacts with dilute hydrochloric acid in a conical flask which is connected to an inverted measuring cylinder in a trough of water. The volume of hydrogen gas produced is measured over a few minutes, and the results are used to plot a graph

Explanation:

Hope it will help you

Answer:

Adding magnesium metal to hydrochloric acid produces hydrogen gas. The magnesium dissolves to form magnesium chloride, MgCl2.

burning. If you observe a gas forming, test for its identity by inserting a glowing wood splint into the mouth of the test tube. ... This is a “glowing splint.” If the splint continues to glow, oxygen gas is present. Do not put the splint into the solution.

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Answer:

solid: ice.

liquid: water

gas: methane

plasma: lightning

Explanation:

Explanation:

Add our site sources in order to be advantage of knowledge

Explanation:

Mass number is the sum of the numbers of protons and neutrons present in the nucleus of an atom.

Answer:

yes

Explanation:

Anything that is verifiable and repeatable is likely to be true. If not verifiable and repeatable, then it may well be completely false, or at least partially false.

This holds for much more than just religious beliefs. What about political thought? One perfect example was when President Obama was pushing his ACA (Obamacare). His facile claim was that with medical coverage for all, the costs of health care would go down. Because people would take better care of themselves, avoiding those major medical bills. But that's just a banality, right? Just words that sound good. I'm not saying that morally, universal health care is wrong. I am saying, don't assume something to be true just because it sounds good. (Of course, health care costs went up, not down.)

Is it true that if you get your car washed every week, it will last longer and cost you less in the long run? Of course not. But it sounds good. People will nod their heads in mindless, lazy agreement. You'll have a cleaner car, you will most likely pay more, and it may last less long, depending on any number of factors. Exactly the same as health care

Answer:

Water vapor molecules in the air near the can cooled when energy from the air transferred to the cold can. These water molecules slowed down, condensed to liquid water, and then froze to become ice. Your can might have some water and some ice on the outside of it.

Explanation:

Explanation:

No, that would be incorrect

Answer:

There arre two main parts of the atom, the nucleus and the orbital rings. The three subatomic particles are contained in each of these, the proton and neutron together in the nucleus and the electrons orbiting in the rings.