Short note of modern periodic table

Answer:

The most accurate and percise player was Josh

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:

atomos

Explanation:

2,500 years ago, Democritus suggested that all matter in the universe was made up of tiny, indivisible, solid objects he called "atomos." However, other Greek philosophers disliked Democritus' "atomos" theory because they felt it was illogical.

Answer:

It will be Ca3P2.

Explanation:

This is kind of a pretty easy question:

- In order to get the number of atoms/entities of Neon, you will have to turn that 1009g of Neon into moles

-And then you have to use the moles and calculate it using Avogadro's Number which is 6.02 x 10^23

number of moles = mass/molar mass of element/compound

n = 1009g/20.18g/mol

n = 50 mol

Number of atoms/entities = 50 x  (6.02 x 10^23)

Number of atoms in 1009g of neon is 3.01 x 10^25 (scientific notation because its a really long number)

Answer:

B- electrons, A- periods, B- groups

Explanation:

[tex]\huge\color{pink}\boxed{\colorbox{Black}{♔︎Answer♔︎}}[/tex]

[tex] \huge\blue{Given}[/tex]

molar mass of CCl4 = 154

density = 1.59 g/cm³

volume = 10 liters

[tex]\huge{\color{magenta}{\fbox{\textsf{\textbf{Solution}}}}}[/tex]

[tex]mass = \frac{density}{volume} \\ mass = \frac{1.59}{10 \times 1000} \\ mass \: = \: 1.59 \times {10}^{ - 4} \\ \\ moles = \frac{mass}{molar \: mass} \\ moles = 0.01 \times {10}^{ - 4} [/tex]

When atoms and molecules speed up or slow down, that is a physical change. When they change state from liquid to solid or from gas to liquid, that is a physical change. ... The ions or molecules can still come back together to form the original substance

The physical change which happens to atoms and molecules in a solution that is strongly heated in a flame is;

Atoms and molecules which are units of matter when strongly heated in a flame have increased internal energy and would undergo a phase change to a more energetic state of matter which is the gaseous state.

As such, the physical change that occurs in them is. increased internal energy.

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Answer:

The expression for the wavelength of radiation is,

λ

1

=R(

n

1

2

1

−

n

2

2

1

)

Substitute values in the above expression,

λ

1

=109677×(

2

2

1

−

4

2

1

)=109677×(

4

1

−

16

1

)=109677×(

64

12

)

λ=4.86×10

−5

cm=486×10

−9

m=486nm.

The line belongs to bluish green colour.

Answer:

The plasma membrane.

Explanation:

membrane, in biology, the thin layer that forms the outer boundary of a living cell or of an internal cell compartment. The outer boundary is the plasma membrane, and the compartments enclosed by internal membranes are called organelles.

A metal electrode composed of  strong reducing agent will have a greater

electrical potential to push electrons toward the electrode composed of a

weak reducing agent.

Strong reducing agents are compounds which donates or loses electrons

with a corresponding increase in the oxidation state. Weak reducing agents

can also be referred to as oxidizing agents and they accept the electrons

from the strong reducing agents which results in a reduction in the oxidation

state.

The strong reducing agent has a greater electric potential which aids the

electrons being pushed towards the electrodes with a weak reducing agent.

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Answer:

Buffers can be made from weak acids or base and their salts.

Explanation:

hope this helps!

(if not tell me in the comments and i will try to help you!)

Answer:

Buffers are made by adding a strong acid or base to a weak acid or base.

Explanation:

Answer:yes

Explanation:

this is because the distance doesnt matter

Answer:

Yes !

Explanation:

The ball will have more molecules.

a basketball filled with liquid water. yes we use 22.4 L/mol as the molar volume for liquid water.

Water is the chemical substance having chemical formula H2O, one molecule of water consist of two hydrogen atoms which are covalently bonded to a single oxygen atom.

The physical property of Water are, it  is a colorless and tasteless liquid,  have extensive hydrogen bonds resulting in unusual properties in the condensed form.

This also have high melting and boiling points. As compared to other liquids, water has a higher specific heat, thermal conductivity, surface tension, dipole moment, etc.

Water is a great solvent and  helps in the transportation of ions and molecules required for metabolism, has high latent heat of vaporization helps in the regulation of body temperature.

It is Amphoteric nature can act as  both acid and base  means that it is amphoteric in nature, it is Electropositive elements which reduce water to hydrogen molecule and it is the source of hydrogen.

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Answer:

zinc oxide is only sparingly soluble in water so best option is to add zinc oxide to diluted hydrocrolic acid

When all the hydrochloric acid (HCl) has reacted, the student can obtain zinc chloride (ZnCl) solution from the reaction mixture by adding ZnO to diluted HCl.

A mixture simply refers to a combination of two (2) or more substances or chemical compounds that are present in varied proportion, and they can be visibly seen with na-ked eyes.

In this scenario, the student can obtain zinc chloride (ZnCl) solution from the reaction mixture when all the hydrochloric acid (HCl) has reacted by adding zinc oxide (ZnO) to diluted hydrochloric acid (HCl) because it's sparingly soluble in water.

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Answer:

Test for carbon dioxide gas.

The reaction between baking soda and citric acid will form sodium ions, citric acid ions, carbon dioxide gas, and water. So all you have to do is add the gas produced (by gas displacement method or something) and test whether the gas is carbon dioxide, with lime water or other methods like hydrogencarbonate indicator. Hope this helped!

Explanation:

Answer:

depends on amount, but the reaction's endothermic (meaning its cold, absorbs heat from surroundings)

I hope it helps.

Answer:7.25

Explanation:

This is because 18.2 - 7.2 = 11 +7.2 = 18.2

Answer:

33.3

Explanation:

if we were to add 29.0 of argon and 4.30 of sulfur and that would come out 33.3.

Answer:

These substances are called amphiprotic. Water, amino acids, hydrogen carbonate ions, and hydrogen sulfate ions are common examples.

Explanation:

A substance is amphoteric (from Greek amphoteros = "each of two") if it can act as an acid or a base.

For example, aluminum hydroxide is amphoteric because it can act as a base and neutralize strong acids.

Answer:

the mass of a tree is primary carbon

Explanation:

the the carbon comes from carbon dioxide during photosynthesis

Answer:

Plants get all the carbon, hydrogen, and oxygen they need from carbon dioxide and water, which they use to build carbohydrates during photosynthesis. To build other kinds of molecules they also need elements like nitrogen, phosphorous, and sulfur. Plants get these as well as other elements from the soil.

Explanation:

This problem is providing information about the volume and concentration of HCl as 505 mL and 0.160 M respectively, and it is asking for the water that have to be added to prepare a 0.100-M solution.

In such a way, we work over the assumption of constant moles in dilution processes, so that we are able to write:

[tex]M_1V_1=M_2V_2[/tex]

Which relates de volume and concentration at the beginning and end of the experiment. This means we can solve for the resulting volume of the solution as a first calculation:

[tex]V_2=\frac{M_1V_1}{M_2}\\\\V_2=\frac{0.160M*505mL}{0.100M}=808mL[/tex]

Hence, the following amount of water must be added:

[tex]V_w=808mL-505mL=303mL[/tex]

Learn more:

Carbon has 6 neutrons, 6 protons and 6 electrons.

An observer in one of those galaxies see the other galaxy moving away at 400000 km/s.

Relative velocity is the velocity of an object with respect to another object, that is the time rate of change of relative position of one object with respect to another object.

Since two galaxy are moving in opposite directions with a velocity of 200,000 km/s. Hence the relative velocity between the two galaxies is 400000 km/s (200000 + 200000)

Therefore an observer in one of those galaxies see the other galaxy moving away at 400000 km/s.

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Answer:

D 400,000km/s

Explanation:

Answer:

the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D)

Explanation:

Answer:

[tex]\boxed {\boxed {\sf 5.6 \ L \ O_2}}[/tex]

Explanation:

We are asked to find the volume of 0.25 moles of oxygen gas.

At standard temperature and pressure or STP, one mole of any gas has a volume of 22.4 liters.

We want to convert 0.25 moles of oxygen gas or O₂ to liters. We will use dimensional analysis, so we must set up a conversion factor.

[tex]\frac {22.4 \ L \ O_2}{1 \ mol \ O_2}[/tex]

We are converting 0.25 moles of oxygen gas, so we multiply the conversion factor by this value.

[tex]0.25 \ mol \ O_2 *\frac {22.4 \ L \ O_2}{1 \ mol \ O_2}[/tex]

The units of moles of oxygen gas cancel.

[tex]0.25 *\frac {22.4 \ L \ O_2}{1 }}[/tex]

[tex]0.25 * 22.4 \ L \ O_2[/tex]

[tex]5.6 \ L \ O_2[/tex]

0.25 moles of oxygen gas occupy 5.6 liters at standard temperature and pressure.