butter melting on warm pancakes is
conduction
convection
radiation

Answer:

150 seconds

Explanation:

Answer:

Zinc weighs 65.38 grams per mole, so we’ve got 0.994 moles of zinc (I’ll worry about sig figs at the end). HCl weighs 36.46 grams per mile, so we’ve got 1.78 moles of HCl. However, two moles of HCl react with one mole of zinc. So only 1.78/2 = 0.890 moles of Zinc are going to react.

One mole of zinc produces one mole of hydrogen, which weigh 2.02 grams per mole. So 0.890 moles * 2.02 grams/mole means 1.90 grams of hydrogen will be produced.

Since we have 2 sig figs in the weights given, the answer should have 2 sig figs, thus 1.9 grams.

This is just an example

Answer:

The correct answer is - option C.  I and Ill only.

Explanation:

One never tastes a unknown chemical in chemistry lab especialy a liquid that can be hazardous. Melting test is for solid as a solution is already a liquid state so melting test can not be perform on it.

The two test can be perform on given sample that are color comparison and boiling test to check if it is substance or a mixture. A misture is prepared from mixing different kind of compounds that can give different kind of color  while a particular substance give a uniform color always or remain colorless.

Boiling test can be helpful in distinguish a mixture from a substance as a particular sybstance always give a particular boiling point but mixture can be varry and depend of the coponents mixed together

Answer:

Method 1 - precision

Method 2 - accuracy

Method 3 - precision

Method 4 - accuracy

Explanation:

The accuracy of a method refers to how close the experimental result is to the accepted value. Accuracy could be checked by carrying out the required test on the standard and not on the sample or by adding a known amount of analyte to the sample so that the results obtained can be carefully compared.

Precision on the other hand, refers to how close the results of a replicate analysis are to each other. In testing for precision, the analysis must be carried out several times, in order to check how close the results are to each other.

Answer:

Volume of solution is 0.88 L.

Explanation:

Given data:

Molarity of solution = 0.750 M

Mass of KNO₃ = 67.0 g

Volume of solution = ?

Solution:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / L of solution

Now we will calculate the number of moles.

Number of moles = mass/molar mass

Number of moles = 67.0 g/ 101.1 g/mol

Number of moles = 0.66 mol

Now we will put the values in molarity formula.

0.750 M = 0.66 mol / L of solution

L of solution  = 0.66 mol / 0.750 M

L of solution  = 0.88 L

Volume of solution is 0.88 L.

Answer:

B?

Explanation:

Answer:

electron

Explanation:

According to the electronic configuration of boron, there are three electrons in the Bohr model of a boron atom.

Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.

Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.

Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.

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Answer:

No. of atom =

no.of moles x avagardro's number xatomicity

= weight /molar mass x No x atomicity

=8.2/142 x6.02x10^23 x 4

=0.346 x 10^23(approximately)

Answer: the particles in the water heats up and the hotter to gets the faster it moves. When there is no where for the heat to go it builds up and pushes its way out and turns to steam when it hits cool air

Explanation:

I know I'm answering super late, but I just want to help others who don't know the answer

Answer:

H. The two elements are in the same group, with Element R just above Element Q.

Explanation:

When answering a question like this, I would highly recommended using a periodic table. I used a periodic table to find the answer to the question.

Answer:

catalase

Explanation:

catalase is enzime the rest are glucides

Answer:

The answer is compaction.

Explanation:

Answer:

39270 J

Explanation:

The quantity of heat required to raise the temperature of a substance from its initial temperature to its final temperature is given by:

Q = mCΔT

m = mass of substance, C = specific heat capacity of substance, ΔT = temperature change = final temperature - initial temperature

Melting point = 0°C, boiling point = 100°C, m = 93.5 g = 0.0935 g, ΔT = boiling point - melting point = 100 - 0 = 100°C, C = 4200 J/kg°C

Q = mCΔT

Q = 0.0935 × 4200 × 100 = 39270 J

Answer:

Its A

Explanation:

Green, blue, indigo lists three parts of sunlight that make up some of the visible spectrum. Hence option with green, blue, indigo is correct.

Electromagnetic spectrum is nothing but the range of wavelengths or frequencies on which electromagnetic radiation extend. it is whole distribution of electromagnetic waves according to frequency or wavelength. Electromagnetic wave is nothing but a photon which carries energy. Photon has frequency, wavelength as well as amplitude.

Electromagnetic spectrum is show in figure.

Range from 4000 angstrom to 7000 angstrom from violet to red respectively shows the visible light

Infrared light is nothing but the heat we feel from the sun. and ultraviolet light is blacked by ozone layer. we can calculate exact value of temperature of the sun rom Stephan's forth power law.

Green, blue, indigo, red and oranges are the colors from visible light, therefore they are part of visible light.

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Answer:

1 - does not flow easily and is difficult to compress

2 -does not flow easily and is difficult to compress.

3 -has lots of space between the charged particles.

4-flows easily but is difficult to compress.

Explanation:

Answer:

I would place 0.5 M solution of the 6.0 stock solution to a 250 mL volumetric flask and then add 250 mL of water.

Explanation:

Answer:

Na⁺,SO₄²⁻

Explanation:

Sodium sulfate is formed by the sodium and sulfate ion.

Sodium is present in group one thus it has only one valence electron. Sodium lose its one valence electron to get complete octet and thus form cation with +1 charge.

On other hand sulfate ion is an anion it carries -2 charge so when it react with sodium there are two sodium atom combine with one sulfate ion inorder to make the compound neutral.

2Na + SO₄²⁻  →  Na₂SO₄

Sodium sulfate is actually form when sodium react with sulfuric acid and hydrogen gas is liberated.

Chemical equation:

Na + H₂SO₄  →  Na₂SO₄ + H₂

Balance chemical equation:

2Na + H₂SO₄  →  Na₂SO₄ + H₂

a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

A compound is a material formed by chemically bonding two or more chemical elements. The type of bond keeping elements in a compound together may vary: covalent bonds and ionic bonds are two common types. The elements are always present in fixed ratios in any compound.

Chemical element, also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed.

is a material made up of two or more different substances which are physically combined.

A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. I

A substance that has a fixed chemical composition throughout is called a pure substance such as water, air, and nitrogen.

hope this help!

Answer:

Here are the definitions of all of them.

Explanation:

Molecule:

a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Compound:

A compound is a material formed by chemically bonding two or more chemical elements. The type of bond keeping elements in a compound together may vary: covalent bonds and ionic bonds are two common types. The elements are always present in fixed ratios in any compound.

Element:

Chemical element, also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed.

Mixture:

is a material made up of two or more different substances which are physically combined.

Chemical Formula:

A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. I

Pure substance:

A substance that has a fixed chemical composition throughout is called a pure substance such as water, air, and nitrogen.

Answer: The mass of product, [tex]H_2O[/tex] is, 36.0 grams.

Explanation : Given,

Mass of [tex]H_2[/tex] = 4.0 g

Mass of [tex]O_2[/tex] = 32.0 g

Molar mass of [tex]H_2[/tex] = 2 g/mol

Molar mass of [tex]O_2[/tex] = 32 g/mol

First we have to calculate the moles of [tex]H_2[/tex] and [tex]O_2[/tex].

[tex]\text{Moles of }H_2=\frac{\text{Given mass }H_2}{\text{Molar mass }H_2}[/tex]

[tex]\text{Moles of }H_2=\frac{4.0g}{2g/mol}=2.0mol[/tex]

and,

[tex]\text{Moles of }O_2=\frac{\text{Given mass }O_2}{\text{Molar mass }O_2}[/tex]

[tex]\text{Moles of }O_2=\frac{32.0g}{32g/mol}=1.0mol[/tex]

Now we have to calculate the limiting and excess reagent.

The balanced chemical equation is:

[tex]2H_2+O_2\rightarrow 2H_2O[/tex]

From the balanced reaction we conclude that

2 mole of [tex]H_2[/tex] react with 1 mole of [tex]O_2[/tex]

From this we conclude that, there is no limiting and excess reagent.

Now we have to calculate the moles of [tex]H_2O[/tex]

From the reaction, we conclude that

2 moles of [tex]H_2[/tex] react to give 2 moles of [tex]H_2O[/tex]

Now we have to calculate the mass of [tex]H_2O[/tex]

[tex]\text{ Mass of }H_2O=\text{ Moles of }H_2O\times \text{ Molar mass of }H_2O[/tex]

Molar mass of [tex]H_2O[/tex] = 18 g/mole

[tex]\text{ Mass of }H_2O=(2.0moles)\times (18g/mole)=36.0g[/tex]

Therefore, the mass of product, [tex]H_2O[/tex] is, 36.0 grams.

Answer:

Number of moles of C produced =  58.08 mol

Explanation:

Given data:

Mass of sugar = 1745 g

Moles of C produced = ?

Solution:

Chemical equation:

C₆H₁₂O₆  +   6H₂SO₄    →     6C + 6(H₂SO₄.H₂O)

Number of moles of sugar:

Number of moles = mass/molar mass

Number of moles = 1745 g/180.16 g/mol

Number of moles = 9.68 mol

Now we will compare the moles of C and sugar.

                 C₆H₁₂O₆          :           C

                      1                  :           6

                    9.68              :          6×9.68 = 58.08 mol

Number of moles of C produced =  58.08 mol

Answer:

v = 3.60Lmol⁻¹s⁻¹ [NH₄CNO]²

Explanation:

The reaction at 65°C of ammonium cyanate to produce urea is:

NH₄CNO → NH₂CONH₂

The general rate law is:

v = K  [NH₄CNO]ˣ

Where v is rate of the reaction, K is rate constant and x represents the order of reaction

Based on the units of the rate constant (Lmol⁻¹s⁻¹ = M⁻¹s⁻¹) the reaction must be order 2 and the rate law:

v = K  [NH₄CNO]²

Answer:

Which type of precipitation freezes when it comes into contact with a cold surface?  

✔ freezing rain

Which type of precipitation is round pellets of ice more than 5 millimeters in diameter?  

✔ hail

Which type of precipitation is water vapor that condenses into ice crystals in clouds?  

✔ snow

Explanation:

The type of precipitation that freezes when it comes into contact with a cold surface is freezing rain.

The type of precipitation that is round pellets of ice more than 5 millimeters in diameter is hail.

The type of precipitation where water vapor condenses into ice crystals in clouds is snow.

Freezing rain is the rain that is maintained at a temperature that's below freezing by ambient air mass. It's made entirely of liquid droplets.

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Answer:

Compound is the answer

Answer:

In a chemical reaction the total mass of all the substances taking part in the reaction remains the same. Also, the number of atoms in a reaction remains the same. Mass cannot be created or destroyed in a chemical reaction.

Stoichiometry must be multiplied by the number that is printed on the element's foot in order to determine how many atoms of a certain element there are in a given molecule.  Therefore, the quantity of atoms inside a reaction doesn't change.

Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms have a central nucleus and electrons that move in a fixed orbit around it. Protons and neutrons are found in the nucleus. Electron has -1 charge while proton has +1 charge.

The combined mass of all of the components involved in a chemical process stays constant. Additionally, the quantity of atoms inside a reaction doesn't change. Chemical reactions cannot produce or destroy mass.

Therefore, the quantity of atoms inside a reaction doesn't change.

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Answer:

The nitrogen atom has 5 electrons in the outermost shell, so it can accept 3 electrons to fulfil the octet structure. Therefore the valency of nitrogen is 3.

Hello!

The answer is that they are a source of energy!

Hope this helps!

Answer:

an atom and inside the atom are protons electrons and nuetrons

Explanation:

Answer:

An Atom

Explanation:

An atom is the most smallest particle of matter, you can't see with the most powerful telescopes or microscopes