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2 years ago

How does a physical change obey the law of conservation of mass?

1 answer:

5 0

Let's consider water.
Regardless of what form it turns into, the mass should remain the same.
It's the same H20.
Add some heat and it becomes water vapor,
cool it down a bit and it becomes ice.
if you make it just right, it becomes water again.

A chemical change would involve the one or more element(s) changing into a different solution all together.
It cannot be reversed unless you use electrolysis or some other method.

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You have a gas at a volume of 9.71 L at a pressure of 209 torr and at 10.1 °C. What

Usimov [2.4K]

Answer:

219.95 °C

Explanation:

Given data:

Volume of gas = 9.71 L

Initial pressure = 209 torr (209/760 = 0.275 atm)

Initial temperature = 10.1 °C (10.1 +273 = 283.1 K)

Final temperature = ?

Final pressure = 364 torr (364/760 =0.479 atm)

Solution:

According to Gay-Lussac Law,

The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.

Mathematical relationship:

P₁/T₁ = P₂/T₂

Now we will put the values in formula:

0.275 atm / 283.1 K = 0.479 atm/T₂

T₂ = 0.479 atm × 283.1 K/ 0.275 atm

T₂ = 135.6 atm. K /0.275 atm

T₂ = 493.1 K

Kelvin to °C:

493.1 K - 273.15 = 219.95 °C

8 0

2 years ago

Wavelengths are often represented in nm. What is the diameter of a helium (He) atom in

lianna [129]

Answer:

Diameter He = 0,1 nm.

Explanation:

Km to nm:

⇒ Diameter He = 1.0 E-13 Km * ( 1000 m / Km ) * ( 1 E9 nm / m )

⇒ Diameter He = 0.1 nm

5 0

2 years ago

Read 2 more answers

If an atom has 15 protons, 11 neutrons, and 16 electrons, what is the atom's electrical charge? A. -5 B. -1 C. +1 D. +5

Helen [10]

Answer:

it's out of the syllabus I can't help

Explanation:

Blanka ajabdjdhsjbsskhsjshsjsvssgshshs

4 0

2 years ago

pleaaase help me asaaap for 150 points my insta is niqsariot_1 dm me for the other 50 points and pleasee answer all of the quest

liq [111]

Answer:

Just here for the points sorry

Explanation:

Minecraft I will not be able to make the weekend of this trip until Sunday evening and I will be away for the rest of the of the week weekend and I will will be back from London tomorrow for lunchtime a week or so if to for for if to go for the it a the the it a couple of rest in the morning the other week night if and time as I we are have the first one in the evening morning so I'll we have an appointment early for in a the class morning and for and then

6 0

2 years ago

Will bromine react with sodium and why?

Archy [21]

When you write down the electronic configuration of bromine and sodium, you get this

Na:
Br:

So here we the know the valence electrons for each;

Na: (2e)
Br: (7e, you don't count for the d orbitals)

Then, once you know this, you can deduce how many bonds each can do and you discover that bromine can do one bond since he has one electron missing in his p orbital, but that weirdly, since the s orbital of sodium is full and thus, should not make any bond.

However, it is possible for sodium to come in an excited state in wich he will have sent one of its electrons on an higher shell to have this valence configuration:

where here now it has two lonely valence electrons, one on the s and the other on the p, so that it can do a total of two bonds.That's why bromine and sodium can form

4 0

3 years ago