Which of the following is an element?
O CuO
O Na
OCH4
H20

Answers

Answer 1

Explanation:

na is element

others are compounds


Related Questions

Give the correct order of apparatus (Crucible, Filter funnel, Test tube, Dropper, Spatula) to show the correct arrangement that can be used to prepare and investigate the nature of pH of a sample of onion solution.

Answers

Answer:

Is it Crucible,Test tube,Dropper,Filter funnel, Spatula

Explanation:

The laboratory apparatus is used to experiment with the chemicals and to hold them. To prepare and investigate the pH of the onion sample apparatus required are the crucible, test tube, dropper, filter funnel, and spatula.

What is pH?

pH is the measurement of the hydrogen or the hydroxide ion concentration in the solution to determine the alkaline or acidic nature of the substance.

The pH of the onion solution can be determined by experimenting with the help of the laboratory apparatus and reagents. A crucible is a container that can withstand high temperatures.

A test tube is a glassware used to hold the substance or chemical in it. Similarly, a dropper is used to draw liquids. The filter funnel separates the filtrate or the solution. A spatula can  be used to remove or add the substance.

Therefore, the correct order of the apparatus is the crucible, test tube, dropper, filter funnel, and spatula.

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Is density a characteristic property of water?

Answers

"Density is a characteristic property of water because the density of any sample of water (at the same temperature) is always the same. The density is 1 g/cm3." - Mazza

It is a characteristic property of water because the density of any sample of water (at the same temperature) is always the same.

PLZ HELP

Observe: To model how hydrogen and oxygen react to make water, type “H2+O2” into the Reactants box and “H2O” into the Products box.

As the equation is written, which element is not in balance? ________________________

Explain: __________

Answers

Answer:

Observe: To model how hydrogen and oxygen react to make water, type “H2+O2” into the Reactants box and “H2O” into the Products box.

As the equation is written, which element is not in balanced?

oxygen isn't balanced...

Explanation:

in reactants there is 2hydrogens and 2 oxygen

but in product there is balanced no if hydrogen bt there is only one no of oxygen

What isotope forms when radon-215 emits two alpha particle and three gamma rays

Answers

Ra215/86-> 2 (alpha)4/2 + 3 0y

Ra215/86-> 8/4 + 3 0y
204/79 AU

May not be true, I forgot the Numbers for gamma rays.

Answer the question below. Use the rubric in the materials for help if needed.

Compare and contrast ionic and covalent bonds by explaining what the electrons do when bonding occurs. Use details to support your answer.

Answers

Answer:

..

...

....

Explanation:

hop it helps.....

Janna, a student of a chemistry class, told her friend that she learnt in class that bottled water is not pure. Kim, her best friend, refused to believe Janna, referring to phrases on the label of the bottle such as “purified drinking water”, “from the purest springs”.
Plan and design an experiment to prove or disprove Janna’s claim
Form an Hypothesis?

Answers

A hypothesis that could prove or disprove Janna’s claim is; bottle water is pure water hence it boils at 100°C.

Pure water is water that contains only hydrogen and oxygen and nothing else. Impure water contains other substances apart from hydrogen and oxygen in a ratio of 2:1.

The hypothesis of our experiment is that;" bottle water is pure water hence it boils at 100°C." A hypothesis is a tentative explanation for an observation.

We can carry out the experiment by bringing about three samples of the bottled water and insert a thermometer in each of the samples then record the initial temperature of the water. The samples are then heated to boiling point and the boiling point of each sample is recorded.

If the sample boil at exactly 100°C then the hypothesis is proven or vice versa.

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How many grams of H2O is needed to produce 0.75 moles of HCL ?​

Answers

2 moles of HCl solution reacts with one mole Calcium Hydroxide

Ca

(

O

H

)

2

One mole of HCl has mass : 36.5 g/mol, two moles of HCl will have mass, 73 g.

One mole of Ca

(

O

H

)

2

has mass 74.1 g

as per equation; 73 g of HCl reacts with 74.1 g of Ca

(

O

H

)

2

1g of HCl reacts with 74.1g / 73 of Ca

(

O

H

)

2

1g of HCl reacts with 1.015 g of Ca

(

O

H

)

2

Fe-C-Cr alloy is covalent or ionic?

Answers

Answer:

covalent....................

How long should you monitor a person who shows signs of a mild allergic reaction

Answers

Answer:

Most reactions occur quickly after ingestion or contact with the allergen, but some can occur up to a few hours later. There can also be a second phase of the reaction when symptoms reoccur. It is important to keep an eye on your child for about 6-8 hours following the first reaction.

Explanation:

The
6.
1. 0,005
5x10 3.
7.
2. 5,050
=
88104
8.
3. 0.0008 =
1 X 103
9.
4. 1,000 =
10
10
5. 1,000,000 =

Answers

Answer:

So the asnwer is 66666666666666666666666666666666666666666666666666666666666666666666666666666666666668888844444444444444444443299997832........................................................4563ygfdjuzgu3456655555555555555555555553444446445444444555554

Explanation:

How many moles of Ag contain 4.49 x 1023 atoms Ag?

Answers

Answer:C, 0.746 mol Ag.

1 mol Ag = 6.022 x 1023 atoms of Ag -> 4.49 x 1023 atoms of Ag x 1mol Ag/6.022 x 1023 atoms -> 0.746 mol Ag

Explanation:

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore,  0.746 mol of Ag contain 4.49 x 10²³ atoms Ag.

What is mole?

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

mole =given number of atoms ÷ 6.022×10²³(Avogadro number)

given number of atoms of Ag=4.49 x 10²³ atoms

Substituting the values

mole= 4.49 x 10²³ ÷ 6.022×10²³

mole =  0.746 mol

Therefore,  0.746 mol of Ag contain 4.49 x 10²³ atoms Ag.

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what is change in science??

Answers

Answer:

A transition from one accepted theory to another or from one employed method to another.

Explanation:

HELP PLZZZZZZZ ASAP
Which best describe the kinetic energy of the particles in solids, liquids, and gases? Check all that apply.


Particles in solids have low kinetic energy.

Particles in solids have high kinetic energy.

Particles in liquids have moderate kinetic energy.

Particles in liquids have low kinetic energy.

Particles in gases have high kinetic energy.

Answers

1,3 and 5 are the correct answers:))
1, 3, 5 are right
Solids have the lowest amount of kinetic energy and particles in gases have the highest

I will make you brainless answer this 1 Question !
Direction: Answer the missing word​

Answers

Answer: This means that the color of light with a higher frequency will have a lower wavelength and valence electron energy level.

Explanation:

A block of aluminum weighs 50.0g it's density is 2.70 g/cm3 what is the volume of a block

Answers

Answer:

18.51g/cm³

Explanation:

Mass=50.0g

Density =2.7g/cm³

Volume =Mass/Density

Volume =50/2.7

Volume =18.51g/cm³

Please tell me the answer, I will mark the first person to answer brainlist

Answers

Answer:

there would be not movement.

What is the significance of the color of the light observed in a line spectrum?

Answers

Answer:

When excited electrons fall back to the ground state, they release energy in the form of photons of light. These photons of light create the colors observed in a line-emission spectrum.

Explanation:

why did rutherford think that all of the alpha particles would go straight through?

Answers

The fact that most alpha particles went straight through the foil is evidence for the atom being mostly empty space. A small number of alpha particles being deflected at large angles suggested that there is a concentration of positive charge in the atom.

Rocks can be classified based on texture. The size of the grains in a rock affects its texture. Coarse-grained rocks have large grains, and fine-grained rocks have small grains.

Rocks formed from magma under Earth’s surface have larger grains than rocks formed from lava on Earth’s surface. This is because magma cools slower underneath the ground than it does above ground.

What kind of rock is this?
A.Igneous
B.Metamorphic
C.Sedimentary


Where would this rock most likely be formed?
A. Along the sides of a volcano
B. On the ocean floor"
C.underneath the Earths surfaces


To which group of rocks would this rock belong?
A. Coarsed-Grained Rocks
B. Fine-Grained Rocks
C. Non-Grained Rocks

Answers

1. is Igneous rock

2. is underneath Earths surface

3. is Coarsed-grained

hope this help!!^^

The kind of rocks is igneous rocks formed along the sides of volcano  and are coarsed-grain rocks.

What are igneous rocks?

Igneous rocks are one of the three main rock types the other two including sedimentary and metamorphic rocks.These rocks are formed by cooling and solidification of lava or magma.

The magma is derived from partial melts in the planet's mantle or crust.Melting is caused by increase in temperature or decrease in pressure or even change in composition.Solidification occurs either below surface which is called as intrusive rocks or on the surface as extrusive rocks.

They are classified according to their texture,mode of occurrence,chemical composition,geometry and mineralogy of rock.The two important variables for classification are mineral composition and cooling history.

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The photoelectron spectrum for the element nitrogen is represented above. Which of the following best explains how the spectrum is consistent with the electron shell model of the ato
f the atom?
A. The leftmost peak represents the valence electrons.

B. The two peaks at the right represent a total of three electrons.

C. The electrons in the ls sublevel have the smallest binding energy

D. The electrons in the 2p sublevel have the smallest binding energy

Answers

Answer:

D. Is the correct option.

Explanation:

2p level contains the electrons furthest from the nucleus in the case of Nitrogen thus it's much easier to disperse/remove the electrons from the shell due to low pull of nucleus energy.

The best explanation of how the spectrum is consistent with the electron shell model of the atom is the electrons in the 2p sub level have the smallest binding energy. Thus, option D is correct.

What is photoelectron spectrum?

Photoemission spectroscopy also known as photoelectron spectroscopy which photoelectric effect is the process in which electron are get energy from external source of energy like sunlight deals with energy measurement of energy emission or electrons emitted from solids, gases or liquids by the process of photoelectric effect,

Photoelectric effect is the process in which electron are get energy from external source of energy like sunlight and get excited and comes in excited state from the ground state due to this process continuos  flow of electron is take place and after that flow of energy is takes place.

Therefore,The best explanation of how the spectrum is consistent with the electron shell model of the atom is the electrons in the 2p sub level have the smallest binding energy. Thus, option D is correct.

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Fe+H2SO4------>????????????

Answers

Fe + H2SO4 → FeSO4 + H2

equation: Iron + Sulfuric acid → Iron (II) sulfate + hydrogen gas

Type of Chemical Reaction: For this reaction we have a single displacement reaction.

Note that this is the chemical reaction that takes place when diluted Sulfuric acid reacts with iron. If you have concentrated Sulfuric acid you will have a different equation.

How much heat is needed to raise a 0.30 g piece of aluminum from 30.C to 150C? The specific heat of aluminum 0.900j/gC

Answers

Answer:

hi

Explanation:

what do an atom ion and isotope of an element have in common?

Answers

They both have the same number of protons but they have different numbers of neutrons.

An atom ion and isotope of an element have in common that both have the same number of protons but they have different numbers of neutrons.

WHAT IS AN ION AND ISOTOPE?

An ion is a charged atom while an isotope is the atoms of an element with the same atomic number but different atomic mass.

For example; Mg2+ is the ionic form of Magnesium while C-12 and C-14 are isotopes of carbon.

Here the ion of an atom will have a different charge but the same mass.

Also The isotope of an atom will have a different mass.

The number of protons V/S the more general atom, an ion has a different number of electrons, and an isotope, a different number of neutrons.

Hence atom ion and isotope of an element have in common that both have the same number of protons but they have different numbers of neutrons.

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How many Joules does it take to raise 1 g of water 2°C

Answers

Answer:

Quantitative experiments show that 4.18 Joules of heat energy are required to raise the temperature of 1g of water by 1°C. Thus, a liter (1000g) of water that increased from 24 to 25°C has absorbed 4.18 J/g°C x 1000g x 1°C or 4180 Joules of energy.

Are cations nonmetals
and anions are metals?

Answers

Answer:

First, each element that forms cations is a metal, except for one (hydrogen), while each element that forms anions is a nonmetal. This is actually one of the chemical properties of metals and nonmetals: metals tend to form cations, while nonmetals tend to form anions. Are positive ions metals or nonmetals?

Explanation:

How would you change liquid water into ice? Be sure to explain what is happening to the energy (the heat)

Answers

Answer:

By putting the liquid water in the fridge

Explanation:

When it is solid the heat will melt to liquid water and if you put it inside a boiling kettle if it boil finished it will bring out gas,if you open it the cover of the kettle you see water if you put it in the fridge and it will be solid again.

Which factor of production would tools fall under?
A) Land
B) Labor
C) capital
D) entrepreneurship

Answers

Answer:

Capital (20 characteristics nanaman bago masend sagot)

Answer:

C) capital

Explanation:

what is the technique for measuring the heat change for a reaction called?

Answers

Answer: calorimetry

Explanation: calorimetry: the measure of the amount of heat involved in a chemical or physical process.

What do these two changes have in common?
boiling an egg
bleaching hair
Select all that apply.

Answers

Answer:

destruction of protein bonds

Explanation:

bleach dyes the hair by opening the hair cuticle and dissolving the color (melanin). The longer you leave it on, the more the protein bonds (keratin) are destroyed.

The heat denatures the protein in the egg by disrupting some of its weak bonds that held the molecule into shape

why should you never place a hot object on the pan of a balance

Answers

Answer:

Because, it would make the pan hot and if it's plastic then it would melt. if it was metal it might make the metal piece hot and you'd risk burning yourself.

Explanation:

You should never place a hot object on the pan of a balance because it can cause the balance to become inaccurate and affect the measurement results.

Balances are precision instruments used to measure the mass of objects with high accuracy. The balance pan and its components are designed to operate under specific conditions, including a stable temperature. When you place a hot object on the balance pan, several issues can arise:

Thermal Expansion: Materials, including metals and plastics, can expand when exposed to heat. Placing a hot object on the pan can cause the pan and its supporting components to expand, potentially affecting the balance's calibration and accuracy.

Uneven Heating: If the hot object is not uniformly heated, it can cause uneven expansion of the balance pan. This can lead to imbalanced weight distribution and inaccurate measurements.

Calibration Shift: The heat from the hot object can cause the materials in the balance to change temperature rapidly, potentially affecting the calibration of the instrument. The balance may require time to stabilize before accurate measurements can be obtained.

Damage to the Balance: Exposing the balance pan to extreme heat can cause warping, cracking, or other structural damage to the pan material. This can permanently impair the balance's performance and accuracy.

To ensure accurate measurements and maintain the integrity of the balance, it's important to allow hot objects to cool to room temperature before placing them on the balance pan. Additionally, using appropriate containers or holders designed for high-temperature applications can help prevent damage to both the hot object and the balance equipment.

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