Bài 19 với ạ, ai giúp em với ❤️❤️❤️❤️❤️

Answer:

Not all plants do need soil to grow

Explanation:

Not all plants need soil to grow. Some just do better in soil compared to other growing mediums. What plants need are minerals and nutrients, such as nitrogen, potassium, and phosphorous. Soil is an effective way of delivering those nutrients cost-effectively. You can also use alternative delivery systems like hydroponics, aeroponics, and aquaponics to achieve the desired effect. However, these are only suitable for growing shallow-rooted plants. Plants with deep roots will always need soil, as will larger plants with spreading roots.

The element that will have the lowest electronegativity is an element with a small number of valence electrons and a large atomic radius.

Electronegativity of an element is the ability or power of that element in a molecule to attract electrons to its Valence electrons.  The following are the properties of electronegativity:

Atomic radius of elements increase down a group because of a progressive increase in the number of shells occupied by electrons which increases the size. But it decreases across a period because electrons are accommodated within the same shell leading to greater attraction by the protons in the nucleus.

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Answer: Its B the guy above me is correct

Answer:

7.5275 x 10^21

Explanation:

Answer:

[tex]\boxed {\boxed {\sf 3 \times 10^{21} \ atoms \ Hg}}[/tex]

Explanation:

We are asked to find how many atoms are in 1 gram of mercury.

First, we convert grams to moles. We use the molar mass or the mass of 1 mole of a substance. These values are equivalent to the atomic masses on the Periodic Table, but the units are grams per mole instead of atomic mass units.

Look up mercury's molar mass.

We convert using dimensional analysis, so we create a ratio using the molar mass.

[tex]\frac { 200.59 \ g \ Hg}{ 1 \ mol \ Hg}[/tex]

We are converting 1 gram of mercury to moles, so we multiply the ratio by this value.

[tex]1 \ g \ Hg *\frac { 200.59 \ g \ Hg}{ 1 \ mol \ Hg}[/tex]

Flip the ratio so the units of grams of mercury cancel out.

[tex]1 \ g \ Hg *\frac{ 1 \ mol \ Hg} { 200.59 \ g \ Hg}[/tex]

[tex]1 *\frac{ 1 \ mol \ Hg} { 200.59}[/tex]

[tex]\frac{ 1} { 200.59} \ mol \ Hg[/tex]

[tex]0.004985293385 \ mol \ Hg[/tex]

Next, we convert moles to atoms. We use Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units) in 1 mole of a substance. In this case, the particles are atoms of mercury.

We will use dimensional analysis and set up another ratio.

[tex]\frac {6.022 \times 10^{23} \ atoms \ Hg}{ 1 \ mol \ Hg}[/tex]

Multiply by the number of moles we calculated.

[tex]0.004985293385 \ mol \ Hg * \frac {6.022 \times 10^{23} \ atoms \ Hg}{ 1 \ mol \ Hg}[/tex]

The units of moles of mercury cancel.

[tex]0.004985293385 * \frac {6.022 \times 10^{23} \ atoms \ Hg}{ 1 }[/tex]

[tex]3.00214368 \times 10^{21} \ atoms \ Hg[/tex]

The original measurement of grams has 1 significant figures, so our answer must have the same. For the number we calculated, that is the ones place. The 0 in the tenths place tells us to leave the 3 in the ones place.

[tex]3 \times 10^{21} \ atoms \ Hg[/tex]

There are approximately 3×10²¹ atoms of mercury in 1 gram of mercury.

Answer:

sodium fusion is changed to sodium sulphide if sulphur is present in the compound

It's O2 which is oxygen....

Answer:

Explanation:

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Answer:

Einstein also in 1905 mathematically proved the existence of atoms, and thus helped revolutionize all the sciences through the use of statistics and probability. Atomic theory says that any liquid is made up of molecules (invisible in 1905)

Explanation:

Answer:

The discoveries of Albert Einstein led to development in the understanding of the atom through the study of quantum mechanics and the electron cloud. In this model, there is still a nucleus with protons and neutrons. But unlike the Bohr model, the electrons exist in a cloud outside the nucleus, much like the fruit around the pit of a peach.

Explanation:

Answer:

by the expirement:

In which mix salt with water

Answer:

Explanation:

25 yard [3 feet / 1 yard] [12 inches / 1 foot] = 25 * 3 * 12 = 900 inches in 25 yards.

Always put the unit you are going to on top and the unit you are coming from on the bottom.

So in this example, you want to going to feet to start with. That's on top. Yards are on the bottom of the first bracket.  In second bracket feet are on the bottom, inches are what you are going to on the top.

Answer:

When we shake the branch of a tree the tree possesses a state of motion whereas the fruits and leaves tend to remain in state of rest. Due to this inertia of rest the fruits and leaves get detached from the branch and because of gravity it falls down.

Explanation:

so it's because of the gravity .

Answer:

Opposite.

Water exhibits negative charge near hydrogen, positive near oxygen.

This is why it is OPPOSITE.

Let me know if this helps!

Water is a polar compound because it exhibits opposite charges. Therefore, option C is correct.

The term polar compound is defined as the compound with distinct regions of positive and negative charge, as a result of bonding with atoms such as nitrogen, oxygen, or sulfur.

Water is a polar compound because the covalent bonds between hydrogen and oxygen in the water molecule are polar in nature. Any molecule with lone pairs of electrons around the central atom is polar compound.

In water there are two atoms are present that are oxygen and hydrogen. Hydrogen has positive charge while oxygen has negative charge,

Thus, Water is a polar compound because it exhibits opposite charges, option C is correct.

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The option which isn't a result of surface tension in water is: c. surface area is maximized.

Water can be defined as a liquid molecule that comprises the chemical element hydrogen and oxygen in the ratio of two to one (2:1).

Surface tension can be defined as a property of liquid such as water, which makes its surface to resist an external force due to the cohesive nature of its molecules.

This ultimately implies that, the surface tension of a liquid is mainly as a result of the cohesive forces existing between its molecules.

Generally, the surface tension of water is typically higher than the surface tension of most liquids.

Due to the effect of surface tension in water;

Additionally, the surface tension of a liquid such as water can be described as an inward force which tends to minimize its surface area rather than maximize its surface area.

In conclusion, surface tension in water doesn't maximize its surface area.

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Answer:

1.26 g

Explanation:

Number of moles of ascorbic acid = concentration × volume

Concentration = 0.447 M

Volume = 16.00 mL

Number of moles = 0.447 × 16/1000

Number of moles = 7.152 × 10^-3 moles

Number of moles= mass/molar mass

Molar mass of ascorbic acid = 176.1 g/mol

Mass = 7.152 × 10^-3 moles × 176.1 g/mol

Mass = 1.26 g

40

Explanation:

because its Saturated

Explanation:

2KCLO3 (s) = 2KCl (s) + 3O2 (g)

Answer:

here's the answer to your question

Answer:

chemical reaction between those a b c it's a reaction which occurs when heating

Answer:

Oxygen does not burn. It is not flammable, but it is an oxidizer.

Explanation

I think you are misunderstanding what is meant by "fire burns up air". Fire does use oxygen when it burns. But it also produces carbon dioxide. An oxygen molecule has two oxygen atoms in it. Fires use this to produce carbon dioxide by adding a single carbon atom from the fire’s fuel (wood, for instance).

hope it'll help:)

Answer:

The blue star is the hottest star.

Explanation:

Red stars are cooler than the sun, with surface temperatures of 3,500 K for a bright red star and 2,500 K for a dark red star. The hottest stars are blue, with their surface temperatures falling anywhere between 10,000 K and 50,000 K

Explanation:

Desposition of solid matter in a solution

Answer:

Explanation:

Lithium Sulphate

Answer:

Lithium sulfate is a white inorganic salt with the formula Li2SO4. It is the lithium salt of sulfuric acid.

Answer:

H2O + SO2 → H2SO3

Explanation:

H2O + SO2 → H2SO3

Answer:

l think this is the answer .

Answer:

A

Explanation:

Two parents are involved in Sexual Reproduction but only one is involved in Asexual Reproduction.

Answer:

Answer:

3

Explanation:

sky is high and I am good.

Answer:

Explanation:

16.7 inches [1 foot / 12 inches] [1 yard / 3 feet] Notice how the units cancel each other out. You do have numbers in the denominator. What you get, looks like this

16.7

------

(12 * 3)

16.7 / 36

0.4639 yrds

Answer:

20,40,60

Explanation:

Let the three parts be 1x, 2x and 3x

The the sum of three parts will be 1x+2x+3x = 120

6x=120

x=120/6

x=20

1x= 20x1=20

2x= 20x2=40

3x= 20x3=60

So 120 is divided in three parts that is 20,40,60

Answer From Gauth Math

Answer:. The concentration is decreased and the volume is increased.

Explanation: Diluting a solution means adding more solvent, usually water, meaning that there is less solute in any sample of the solution. Adding more solvent means that the volume of the solution will increase.

Answer:

give me brainliest pls

Explanation:

Volumetric flasks

Volumetric labware is for measuring liquids with precision. Volumetric flasks, burettes, and pipettes made for measuring small amounts of liquid are the most accurate, with tolerances of less than ±0.02.

Answer:

A pipette is a laboratory instrument used to measure out or transfer small quantities of liquid, in volumes of milliliters (mL), microliters (μL).