Chemical properties of water and oxygen for class 8

Answer:

Explanation:

The balanced equation says that we'll get 1 mole of H2 for every 1 mole of Mg.  50 grams of H is 50g/2 g/mole = 25 moles of H2.  That means we'll need 25 moles of Mg.  Convert that into grams:  (25 moles Mg)*(24.3 g/mole) = 607 grams Mg.  

At STP, all gases occupy 22.4 liters/miole.  That means 25 moles of H2 would occupy (25 moles)*(22.4 liters/mole) = 560 liters.

Answer:

The warmer the water gets the particles begin to expand and starts vibrating

THIS IS UR ANSWERPLS MARK ME AS BRAINLIEST..

Answer:

Box#:

1:CoS

2:Co2S3

3:CoSO4

4:Co2(SO4)3

5:CoSO3

6:Co2(SO3)3

Explanation:

1:Co(II) is -2 and S is -2, so the charges cancel

2:Co(III) is -3 and is -2, so you cross the charges but do not reduce

3:Co(II) is -2 and SO4 is -2, so the charges cancel

4:Co(III) is -3 and SO4 is -2 so the charges cross but do not reduce

5:Co(II) is -2 and SO3 is -2 so the charges cancel

6:Co(III) is -3 and SO3 is -2 so the charges once again cross

Answer:

Cobalt (II) sulfide → CoS

Cobalt (III) sulfide → Co₂S₃

Cobalt (II) sulfate → CoSO₄

Cobalt (III) sulfate → Co₂(SO₄)₃

Cobalt (II) sulfite → CoSO₃

Cobalt (III) sulfite → Co₂(SO₃)₃

Answer:

Explanation:

Pencils are though formed of wood that acts as a bad conductor of electricity, quite strangely pencils can be electrically charged.

Here pencils have non-metal carbons present in its graphite tip and this makes the pencils charged.

When this pencil is held near the water of the tap, the hydrogen ions get attracted and thereby the water gets attracted to the pencil.

Water, however, is an excellent conductor of electricity and therefore water and electricity are a dangerous combination.

Answer:

Incase you have H and F and another H and F

Answer:

Robert Boyle

Explanation:

En muchos textos se suele considerar a Robert Boyle como el científico que introdujo en la Química un concepto de elemento diferente al empleado por los aristotélicos o por los alquimistas y que sirvió de antecedente al que formulara Lavoisier en 1789.

Answer:

Tthe 3-carbon pyruvate molecule made in glycolysis loses a carbon to produce a new, 2-carbon molecule called acetyl CoA. The carbon that is removed takes two oxygens from pyruvate with it, and exits the body as carbon dioxide (CO 2​start subscript, 2, end subscriptt).

Explanation:

Answer:

Explanation:

2,4 di methyl means that there are 2 methyl groups on the 2 and 4 carbons. hexane means there are 6 carbons in total for the carbon chain

first pic

3,3 diethyl means there are 2 ethyl groups on the 3 carbon chain. 4 mthyl means 1 methyl group on the 4 carbon chain, 5 propyloctane means that there are 1 propylo on the 5 carbon chain. and that the carbon chain is a octane meaning 8 carbons.

second pic

Answer:

please mark as brainliest

Explanation:

Any substance that inhibits the growth and replication of a bacterium or kills it outright can be called an antibiotic. Antibiotics are a type of antimicrobial designed to target bacterial infections within (or on) the body. This makes antibiotics subtly different from the other main kinds of antimicrobials widely used today:

Antiseptics are used to sterilise surfaces of living tissue when the risk of infection is high, such as during surgery.

Disinfectants are non-selective antimicrobials, killing a wide range of micro-organisms including bacteria. They are used on non-living surfaces, for example in hospitals.

Of course, bacteria are not the only microbes that can be harmful to us. Fungi and viruses can also be a danger to humans, and they are targeted by antifungals and antivirals, respectively. Only substances that target bacteria are called antibiotics, while the name antimicrobial is an umbrella term for anything that inhibits or kills microbial cells including antibiotics, antifungals, antivirals and chemicals such as antiseptics.

Most antibiotics used today are produced in laboratories, but they are often based on compounds scientists have found in nature. Some microbes, for example, produce substances specifically to kill other nearby bacteria in order to gain an advantage when competing for food, water or other limited resources. However, some microbes only produce antibiotics in the laboratory

Answer:

Antibiotics commonly are produced by soil microorganisms and probably represent a means by which organisms in a complex environment, such as soil, control the growth of competing microorganisms. Microorganisms that produce antibiotics useful in preventing or treating disease include the bacteria and the fungi.

Explanation:

source: trust me bro

Answer:

he presence of nucleus which contains genetic material and is enclosed by a nuclear membrane sets them apart from prokaryotic cells. All complex organisms are eukaryotic and they reproduce by mitosis or meiosis. Eukaryotic cells are typically much larger than those of prokaryotes.

Explanation:

When the mixture of ions undergoes electrolysis, Br- is most easily oxidized.

Electrolysis refers to the decomposition of a solution by the passage of direct current through it. During electrolysis, a specie is oxidized and another specie is reduced since it is a redox reaction.

Among all the ions; Mg2+ , Cu2+ ,F-, Cl-, Br-, the ion that is most easily oxidized in Br- which is oxidized to Br2.

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Answer:

Paracetamol

Formula

C8H9NO2

Answer:

The awnser is Ionic bond

Answer: Na2SO4

The molecular formula for sodium sulphur and oxygen​ is: (Na2SO4)

,  Hope this helps :)

Have a great day!!

Answer:

1:

•a typical metal tends to have a higher melting and boiling point than a typical non metal which has a low melting and boiling point

•a typical metal tends to have a shiny appearance than a typical non metal which has a dull apearance

•and finally, a typical metal is a good conductor of electricity and heat while a typical non metal isn't

2:

elements E and C

3:

a, it doesn't conduct electricity

b, it's a good conductor of heat/ has a high melting point/ has a high boiling point (you can choose either that sits right with you)

n-propylbenzene will travel the largest distance because it interacts most effectively with the stationary phase followed by phenol and benzoic acid will travel the least distance because it interacts poorly with the mobile phase.

Thin layer chromatography involves the separation of a mixture using a stationary phase made of  silica gel on a glass plate and an appropriate mobile phase. The extent of separation is highly dependent on the magnitude of interaction between the solute and the mobile phase. and stationary phase.

The first step in thin layer chromatography is to make a thin mark at the bottom portion of the plate then spot the plate with the sample. The mobile phase is now introduced into the TLC chamber a little below the mark. The plate is now placed in the stationary phase such that the mark is above the solvent level.

The TLC chamber is now covered and enough time is allowed for separation to occur. The spots can be seen using a suitable indicator dye or with a the aid of UV light

After the  separation of a homogeneous, liquid mixture containing benzoic acid, n-propylbenzene, and phenol, provided a 4:1 hexane to ethyl acetate solution as the eluent, we can see that n-propylbenzene will travel the largest distance because it interacts most effectively with the stationary phase followed by phenol and benzoic acid will travel the least distance because it interacts poorly with the mobile phase.

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Answer:

B

Explanation:

Answer:

It is a type of radiant energy that's invisible to human eyes but that we can feel as heat.

Considering the definition of ionization energy, the highest ionization energy belongs to the element:

a. Be

b. Ar

c. Cl

Electrons are held in atoms by their attraction to the nucleus, which means that energy is needed to remove an electron from the atom.

You should keep in mind that the electrons of the last layer are always lost, because they are the weakest attracted to the nucleus.

Ionization energy, also called ionization potential, is the necessary energy that must be supplied to a neutral, gaseous, ground-state atom to remove an electron from an atom. When an electron is removed from a neutral atom, a cation with a charge equal to +1 is formed.

In a group, the ionization energy increases upwards because when passing from one element to the bottom, it contains one more layer of electrons. Therefore, the valence layer electrons, being further away from the nucleus, will be less attracted to it and it will cost less energy to pluck them.

In the same period, in general, it increases as you shift to the right. This is because the elements in this way have a tendency to gain electrons and therefore it will cost much more to tear them off than those on the left which, having few electrons in the last layer will cost them much less to lose them.

Considering all the above, from each of the pairs, the highest ionization energy belongs to the element:

a. Be

b. Ar

c. Cl

Learn more:

We know that water is tasteless, odorless, and transparent. In small quantities, it is also colorless. However, when a large amount of water is observed, as in a lake or the ocean, it is actually light blue in color. The blue hue of water is an intrinsic property and is caused by selective absorption and scattering of white light. These and other properties of water depend on its chemical structure.The transparency of water is important for organisms that live in water. Because water is transparent, sunlight can pass through it. Sunlight is needed by water plants and other water organisms for photosynthesis.Chemical Structure of WaterEach molecule of water consists of one atom of oxygen and two atoms of hydrogen, so it has the chemical formula H2O. The arrangement of atoms in a water molecule explains many of water’s chemical properties. In each water molecule, the nucleus of the oxygen atom (with 8 positively charged protons) attracts electrons much more strongly than do the hydrogen nuclei (with only one positively charged proton). This results in a negative electrical charge near the oxygen atom (due to the "pull" of the negatively charged electrons toward the oxygen nucleus) and a positive electrical charge near the hydrogen atoms. A difference in electrical charge between different parts of a molecule is called polarity. A polar molecule is a molecule in which part of the molecule is positively charged and part of the molecule is negatively charged.

•Hydrogen Bonding-

Opposite electrical charges attract one another. Therefore, the positive part of one water molecule is attracted to the negative parts of other water molecules. Because of this attraction, bonds form between hydrogen and oxygen atoms of adjacent water molecules. This type of bond always involves a hydrogen atom, so it is called a hydrogen bond. Hydrogen bonds are bonds between molecules, and they are not as strong as bonds within molecules. Nonetheless, they help hold water molecules together.

•Sticky, Wet Water-

Water has some unusual properties due to its hydrogen bonds. One property is cohesion, the tendency for water molecules to stick together. The cohesive forces between water molecules are responsible for the phenomenon known as surface tension. The molecules at the surface do not have other like molecules on all sides of them and consequently they cohere more strongly to those directly associated with them on the surface. For example, if you drop a tiny amount of water onto a very smooth surface, the water molecules will stick together and form a droplet, rather than spread out over the surface. The same thing happens when water slowly drips from a leaky faucet. The water doesn't fall from the faucet as individual water molecules but as droplets of water.

•Density of Ice and Water-

The melting point of water is 0°C. Below this temperature, water is a solid (ice). Unlike most chemical substances, water in a solid state has a lower density than water in a liquid state. This is because water expands when it freezes. Again, hydrogen bonding is the reason. Hydrogen bonds cause water molecules to line up less efficiently in ice than in liquid water. As a result, water molecules are spaced farther apart in ice, giving ice a lower density than liquid water. A substance with lower density floats on a substance with higher density. This explains why ice floats on liquid water, whereas many other solids sink to the bottom of liquid water.In a large body of water, such as a lake or the ocean, the water with the greatest density always sinks to the bottom. Water is most dense at about 4°C. As a result, the water at the bottom of a lake or the ocean usually has temperature of about 4°C. In climates with cold winters, this layer of 4°C water insulates the bottom of a lake from freezing temperatures. Lake organisms such as fish can survive the winter by staying in this cold, but unfrozen, water at the bottom of the lake.

Hope it helps

Answer:

1. highest is 25.7c° and lowest is 20.0c°

2.Is Exothermic.  An Endothermic Reaction is a chemical reaction that absorbs energy in the form of light or heat. In it, the energy or enthalpy of the reactants is less than that of the products. An Exothermic Reaction is a chemical reaction that gives off energy in the form of light or heat.

3. Reactans.

4. The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction.

Answer:

O=c=o

Explanation:

co2is nonpolar and it has linear molecular shape

The total charge on an atom comes from protons and electrons.

The proton is positively charged while the electron is negatively charged. A neutral atom would have an equal number of protons and electrons.

An atom with more protons than electrons will be positively charged while those with more electrons than protons will be negatively charged.

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Answer:

They cannot be broken down any further

Explanation:

An element is a substance that cannot be broken down into a simpler format. They are distinguished by a unique atomic number. The elements are organized by their atomic number in the periodic table, which highlights elements with similar properties.

Answer:

[tex]\implies \sf D = \dfrac{PM}{RT}[/tex]

[tex]\implies \sf 3.35= \dfrac{1 \times M}{ \frac{1}{12} \times 298}[/tex]

[tex]\implies \sf 3.35= \dfrac{12\times M}{ 298}[/tex]

[tex]\implies \sf 3.35 \times 298= 12\times M[/tex]

[tex]\implies \sf 998.3= 12\times M[/tex]

[tex]\implies \sf M = \dfrac{998.3}{12} [/tex]

[tex]\implies \bf M = 83.1917 \: \frac{g}{mol} [/tex]

Answer:

Ionic bonds result from the transfer of electrons from one atom to another

Explanation:

In covalent bonds, atoms share electrons, whereas in ionic bonds atoms transfer electrons. The reaction components of covalent bonds are electrically neutral, whereas for ionic bonds they are both charged.Covalent bonds are formed between two non-metals, whereas ionic bonds are formed between a metal and non-metal.  

Answer:

Covalent bonds are defined as sharing of electrons, ionic bonds are the result of transferred electrons;

Covalent bonds form between non-metals (elements) and ionic bonds form between metal and non-metals (ions)

Explanation:

Mix cold water and flour in a jar. Stir very well. After a few minutes, you can see sediments

at the bottom of the jar. How could you separate the sediments from the water?

3. After the members of the family ate different kinds of fruits, you gathered the seeds. You

mixed them in a basin. Later on, your mother instructed you to separate each kind of seed.

How will you separate each kind of seed?

4. Mix sand and water in a basin. After five minutes, try to separate the sand from the water.

How will you do this?

5. Dissolve one teaspoon of sugar in a cup of water (mixture of solid and liquid.) After three

minutes, separate the sugar from the water. How will you do it?

SANA PO MASAGOTAN NYU NG TAMA

Answer:

[Xe] 6s2

Explanation:

hope it helps Electron configuration