what did you learn in chemistry?​

Answer:

Dmitri Mendeleev

Explanation:

Dmitri Mendeleev a Russian Chemist arranged elements on the periodic table according to their atomic mass. He used this arrangement to predict some of the properties of the missing element.

Answer:

the chemical element of atomic number 16, a yellow combustible nonmetal.

Explanation:

ur welcome plz give me brainliest

Explanation:

A pale-yellow, brittle nonmetallic element that occurs widely in nature, especially in volcanic deposits, minerals, natural gas, and petroleum. It is used to make gunpowder and fertilizer, to vulcanize rubber, and to produce sulfuric acid.

Answer:

1.23345*10^11

5.768*10^(-5)

3.456*10^(-2)

2.28*10^9

8.0970*10^4

Explanation:

You just need to count the number of zeros and move the values backward and forward to get the scientific notation.

Answer:

It must be neutral because there are 9 positive atoms and 9 megative charged atoms they cancels each other out and make the particle neutral

Explanation:

I hope this helps!!

Answer:

0.033 M

Explanation:

From the question given above, the following data were obtained:

Volume of stock solution (V1) = 250 mL

Molarity of stock solution (M1 ) = 0.10 M

Volume of diluted solution (V2) = 750 mL

Molarity of diluted solution (M2) =.?

Thus, we can obtain the molarity of the diluted solution by using the dilution formula as illustrated below:

M1V1 = M2V2

0.1 × 250 = M2 × 750

25 = M2 × 750

Divide both side by 750

M2 = 25/750

M2 = 0.033 M

Therefore, the molarity of the diluted solution is 0.033 M.

Answer:

Please find the answers to the frequency and energy to each question below

Explanation:

Using the formulas;

λ = v/f

E = hf

Where;

λ = wavelength (metres)

v = speed of light (2.998 × 10^8 m/s)

f = frequency (Hz)

E = Energy of photon (J)

h = Plancks constant (6.63 × 10^-34 J.s)

1.) λ = 568cm = 5.68m

f = v/λ

f = 2.998 × 10^8 ÷ 5.68

f = 0.5278 × 10^8

f = 5.278 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 5.278 × 10^7

E = 34.99 × 10^(-34+7)

E = 3.499 × 10^-26 J

2). λ = 726cm = 7.26m

f = v/λ

f = 2.998 × 10^8 ÷ 7.26

f = 0.413 × 10^8

f = 4.13 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 4.13 × 10^7

E = 27.38 × 10^(-34+7)

E = 2.74 × 10^-26 J

3). λ = 482cm = 4.82m

f = v/λ

f = 2.998 × 10^8 ÷ 4.82

f = 0.622 × 10^8

f = 6.22 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 6.22 × 10^7

E = 41.24 × 10^(-34+7)

E = 4.124 × 10^-26 J

4). λ = 879cm = 8.79m

f = v/λ

f = 2.998 × 10^8 ÷ 8.79

f = 0.341 × 10^8

f = 3.41 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 3.41 × 10^7

E = 22.61 × 10^(-34+7)

E = 2.26 × 10^-26 J

5). λ = 167cm = 1.67m

f = v/λ

f = 2.998 × 10^8 ÷ 1.67

f = 1.795 × 10^8

f = 1.795 × 10^8 Hz

E = hf

E = 6.63 × 10^-34 × 1.795 × 10^8

E = 11.9 × 10^(-34+8)

E = 1.19 × 10^-25 J

6). λ = 572cm = 5.72m

f = v/λ

f = 2.998 × 10^8 ÷ 5.72

f = 0.524 × 10^8

f = 5.24 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 5.24 × 10^7

E = 34.74 × 10^(-34+7)

E = 3.474 × 10^-26 J

Answer/Explanation:

A) The independent(test) variable controls the dependent variable. A good way to think about this is that the independent variable has nothing that effects itself. The dependent variable is 'dependent' or reliant on the independent variable.

Answer:

A

Explanation:

Answer:

[tex]36.273\ \text{kJ/mol}[/tex]

Explanation:

m = Mass of LiCl = 2.5 g

M = Molar mass of LiCl = 42.394 g/mol

c = Specific heat of water = [tex]4.186\ \text{J/g}^{\circ}\text{C}[/tex]

[tex]\Delta T[/tex] = Change in temperature = [tex]29.11-24=5.11\ ^{\circ}\text{C}[/tex]

[tex]m_w[/tex] = Mass of water = [tex]\rho V=1\times 100=100\ \text{g}[/tex]

Number of moles

[tex]n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{2.5}{42.394}\\\Rightarrow n=0.05897\ \text{mol}[/tex]

Heat is given by

[tex]Q=m_wc\Delta T\\\Rightarrow Q=100\times 4.186\times 5.11\\\Rightarrow Q=2139.046\ \text{J}[/tex]

Enthalpy is given by

[tex]\Delta H=\dfrac{Q}{n}\\\Rightarrow \Delta H=\dfrac{2139.046}{0.05897}\\\Rightarrow \Delta H=36273.46\ \text{J/mol}=36.273\ \text{kJ/mol}[/tex]

The enthalpy for the dissolution is [tex]36.273\ \text{kJ/mol}[/tex].

Answer:

Explanation:

To convert a temperature from degree Celsius to Kelvin add 273 to the value in degree Celsius

That's

K = 273 + °C

where

K is the temperature in Kelvin

°C is the temperature in degree Celsius

From the question we have

K = 273 + 133

We have the final answer as

Hope this helps you

Answer:

The answer is Boling Point

Explanation:

The properties of the sample which is most helpful to determine if the liquid is water is (D) . the boiling point of the liquid

The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.

The boiling point of a liquid varies depending upon the surrounding environmental pressure

Substances at different states usually possess certain properties that distinguishes them. For example, in this case involving a student who was given a sample of an unknown liquid to test in the laboratory, he thinks that the unknown liquid is water.

Specific properties of the unknown liquid can be used to identify whether it is water or not.

One property that can be used to ascertain whether or not it is water is the boiling point of the liquid. This is because specific liquids have specific boiling point. So if the unknown liquid has a boiling point of 100°C, then it can be ascertained to be water.

Therefore, The properties of the sample which is most helpful to determine if the liquid is water is (D) . the boiling point of the liquid

Learn more about Boiling point here ;

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Answer:

21%

Explanation:

It's a mixture of different gases. The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen.

Answer:

Answer:

Grating

Explanation:

I think you need to grate it

Answer: The sugar would dissolve in water. You could then pour off the solution and wash the remaining sand with a bit more water. Heat the water to evaporate it from the sugar, and the two are separate

Explanation:

Answer:

ethylene molecule. The molecule has trigonal planar geometry around its carbon atoms

Answer:

Percent yield = 98%

Explanation:

Given data:

Actual yield of ZnCl₂ = 140.15 g

Theoretical yield of ZnCl₂  = 143 g

Percent yield = ?

Solution:

Formula:

Percent yield = (actual yield / theoretical yield )× 100

Percent yield = (140.15 g/ 143 g)× 100

Percent yield = 0.98 × 100

Percent yield = 98%

Answer:

Kinetic energy is the energy possessed by an object in motion.

Answer:

A wave with a higher frequency have a shorter wavelength, the higher the sound it, the closer the arcs of the wavelength are, the faster the sound is, the shorter they are.

According to scied.ucar.edu  ~  "The frequency of a wave is inversely proportional to its wavelength. That means that waves with a high frequency have a short wavelength, while waves with a low frequency have a longer wavelength. Light waves have very, very short wavelengths."

Hope this helps

Explanation:

May I have brainliest please? :)

A wave with a higher frequency has a longer wavelength is a false.

A wave with a higher frequency has a longer wavelength is a false statement because shorter wavelength have higher frequency and also higher energy.

We know that longer wavelength of a wave having shorter frequency and shorter energy while on the other hand, the shorter wavelength of a wave having higher frequency and higher energy so we can conclude that the statement is false.

Learn more about frequency here: https://brainly.com/question/254161

Answer:

yes

Explanation:

as the salt is a polar compound which means that its dissolvable in water

so the salt would be solute and the water is the solvent

Answer:

A.

General Formulas and Concepts:

Chemistry - Stoichiometry

Explanation:

Step 1: Define

Given:   4 mol Mg(OH)₂

RxN:   MgCl₂ + 2KOH → Mg(OH)₂ + 2KCl

Step 2: Identify Conversions

Molar Mass of K - 39.10 g/mol

Molar mass of O - 16.00 g/mol

Molar mass of H - 1.01 g/mol

Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol

Step 3: Stoichiometry

[tex]4 \ mol \ Mg(OH)_2(\frac{2 \ mol \ KOH}{1 \ mol \ Mg(OH)_2} )(\frac{56.11 \ g \ KOH}{1 \ mol \ KOH} )[/tex]

Answer:

check the attachment/picture below!

Explanation:

I had just taken that quiz! :D

Answer:

d = 20.89 g/cm³

Explanation:

Given data:

Length of block = 4.20 cm

width of block = 3.80 cm

Height of block = 5.40 cm

Mass of block = 1800 g

Density of block = ?

Solution:

First of all we will calculate the volume.

V = l×w×h

V = 4.20 cm ×3.80 cm× 5.40 cm

v = 86.18 cm³

Density:

d =m/v

d =1800 g/ 86.18 cm³

d = 20.89 g/cm³

Answer:

im pretty sure its the second one

Answer:

at the center of the mid-ocean ridge

Explanation:

Answer:

Anywhere along the mid-atlantic ridge

Explanation:

It goes through a bunch of history, such as the Continental Drift Theory from Alfred Wegener to Harry Hess proving it. So, in WW2, Harry Hess was in the navy (he was a geographer/geologist who noticed while using sonar, that the waves were bouncing back uneven when they launched sonar, which proved the ocean floor was not flat like how they used to beleive it was.

Anyways, they discovered the mid-atlantic ridge, (you can see it on maps! Go to a search engine's maps and look at the atlantic ocean and you can see this weird ridges along with these (not latitude or longitude) lines.

The mantle in the Earth's layers is moving the plates (continental and oceanic plates to be exact) from convection currents, and there is very deep trenches in the Earth, such as the Mariana Trench. The mantle pushes magma through some holes, and it rises and cools in the ocean, which is then pushed aside by more solidifiying magma in a process called seafloor spreading. Magma is called lava when it comes out of the place where it comes from, so the lava cools into rock which is called basalt too.

Hope this helps anyone in the future!

I don't mean to be a boomer by necroposting

dont roast me plz

Answer:

a Hg(NO3)2

b CoBr2,CoBr2·6H2O,CoBr2·2H2O

Explanation:

Answer:

b

Explanation:

An echo or a reverberation can result from the reflection of sound waves off physical surfaces. Small rooms with dimensions of 17 meters or fewer, breadth, and length frequently experience reverberation.

When two different media come together at an interface, a wavefront might change direction so that it returns to the first medium, which is known as reflection. The reflection of light, sound, and water waves are typical examples.

According to the law of reflection, the angle of incidence and angle of reflection are equal. The reflected wave will typically be inverted for mechanical waves traveling from a less dense medium into a more dense medium.

A portion of a wave will often bounce back into the original medium when it encounters the interface between two different media. We call this process "reflection." Optical reflection in mirrors, where light waves reflect off a smooth surface, is a well-known example of reflection.

Thus, An echo or a reverberation can result from the reflection of sound waves off physical surfaces.

To learn more about reflection, follow the link;

https://brainly.com/question/15487308

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Answer:

because the neutrons is always equal or greater there is never a less then in neutrons.

Explanation:hope this helped