why is it called the periodic table of elements (why is the word periodic in it)

Answer:

A: A substance that can be separated into two or more substances only by chemical means.

Explanation:

The best answer for this would be A. A compound in general is when two or more elements are bonded chemically. That is, the elements are joined in a chemical reaction. An example of a compound is table salt; (sodium chloride) NaCl. It, like all chemicals, can be separated into both of its components, so B is out. The other two answers basically say is it either only chemical or physical means that can separate it, when the answer is that it is only chemical changes that can separate a compound. There can be a reaction when a compound is broken up. You might think that you can separate salt crystals with a hammer or some physical force, but that's only the salt lattice, not the Na and Cl coming apart. Also, for the compound water, H2O, the Hydrogen and Oxygen can be separated by running an electric current through the water sample. This chemically alters the water molecule and splits it up, which is a chemical change. So, to sum up here, you can only use chemical means to separate a compound. Take care!

A compound is a substance that can be separated into two or more of its constituents by chemical methods. So the correct option is A.

Any material made up of similar molecules with atoms from two or more different chemical elements is referred to as a chemical compound.

Atoms from more than 100 distinct chemical elements, both in their pure forms and when mixed to create chemical compounds, make up all matter in the universe. A sample of a pure element has just the atoms that are distinctive of that element, and each element's atoms are distinct.

For instance, the atoms that make up carbon differ from those that make up iron, which differs from those that makeup gold. Every element has a distinct symbol that is made up of one, two, or three letters that come from either the element's current name or its original name.

Therefore the correct option is A.

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Answer:

False, the empirical formula denotes the smallest whole-number ratio of atoms in a compound

Explanation:

a molecular formula is the total number of atoms in the compound

Answer:

Mass = 917.4 g

Explanation:

Given data:

Number of molecules = 3.00 ×10²⁴ molecules

Mass in gram = ?

Solution:

1 mole contain 6.022 × 10²³ molecules

3.00 ×10²⁴ molecules × 1 mol /  6.022 × 10²³ molecules

0.5×10¹ mol

5 mol

Mass in gram:

Mass = number of moles  × molar mass

Mass = 5 mol  × 183.48 g/mol

Mass = 917.4 g

Answer:

3 moles of Oxygen

Explanation:

The chemical formula of a compound is a representation which shows all the elements therein and the mole relationship between them expressed as subscripts.

   NaHCO₃  implies:

      1 mole of baking soda contains:

     1 mole of Na

     1 mole of Hydrogen

     1 mole of carbon

  And 3 moles of Oxygen

Answer:

diffusion

Explanation:

is the movement of molecules from high concentration to low concentration.

Answer:

it runs the risk of triggering earthquakes. releases harmful gases

Answer:

i think i like 14 or 8 atom

Explanation:

Answer:

[tex]1)kidneys \\ 2)excretory \\ \: \: 3)valve \\ \: 4)reproductive \\ \: 5)circulatory \\ \: 6)circulatory \\\ \: 7)trachea \\ \\ \\ plzz \: mark \: as \: brainliest[/tex]

Answer shallow ocean

Explanation:

i think

2.0 mol O₂

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[RxN - Balanced]   CH₄ + 2O₂ → CO₂ + 2H₂O

[Given]   36 g H₂O

Step 2: Identify Conversions

[RxN] 2 mol H₂O → 2 mol O₂

Molar Mass of H - 1.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of H₂O - 18.02 g/mol

Step 3: Stoichiometry

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

1.99778 mol O₂ ≈ 2.0 mol O₂

In the given question, 136293840 seconds are present in 4.3 years.

A second is a unit of time that is equal to 1/60th of a minute and is used to measure short periods of time.

To convert 4.3 years to seconds, we can use the following conversion factors:

1 year = 365.25 days (accounting for leap years)

1 day = 24 hours

1 hour = 60 minutes

1 minute = 60 seconds

So, we can start by multiplying the number of years by the number of days per year:

4.3 years [tex]\times[/tex] 365.25 days/year = 1577.475 days

Next, we can multiply the number of days by the number of hours per day:

1577.475 days [tex]\times[/tex] 24 hours/day = 37859.4 hours

Then, we can multiply the number of hours by the number of minutes per hour:

37859.4 hours [tex]\times[/tex] 60 minutes/hour = 2271564 minutes

Finally, we can multiply the number of minutes by the number of seconds per minute to get the total number of seconds:

2271564 minutes [tex]\times[/tex] 60 seconds/minute = 136293840 seconds

Therefore, in 4.3 years there are approximately 136293840 seconds.

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Answer:

it is D

Explanation:

edge

Answer:

It's

Explanation:

I took the edge 2023

Answer:

b

Explanation:

Answer:

there is no picture so we can't tell why the containers are heavy

Answer:

p4

Explanation:

Answer:

493.9°C

Explanation:

Given parameters:

Initial pressure  =0.815atm

Initial temperature  = 265C  = 265 + 273  = 538k

Initial volume  = 416mL  = 0.416L

New volume    = 593mL  = 0.593L

Unknown:

New temperature =?

Solution:

Since we are dealing with constant pressure condition, we apply charles's law.

It states that the volume of a fixed mass of gas varies directly as its absolute temperature if the pressure is constant.

    Mathematically ;

         [tex]\frac{V1}{T1}[/tex]    = [tex]\frac{V2}{T2}[/tex]  

V1 is the initial volume                     V2 is the new volume

T1 is the initial temperature             T2 is the new temperature

   [tex]\frac{0.416}{538}[/tex]   = [tex]\frac{0.593}{T2}[/tex]    

           T2 = 766.9K;

  In °C  = 766.9 - 273 = 493.9°C

Answer: Selective breeding?

Explanation:

A farmer has bred his pineapple plants from the sweetest pineapples from his last harvest to get even sweeter pineapple plants. This is an example of selective breeding.

By determining which male and female animals or plants will normally reproduce sexually and generate offspring together, people can employ animal and plant breeding to selectively acquire specific phenotypic features.

But excessive selective breeding can result in the emergence of hereditary diseases. And in fact, many dog breeds today experience major health problems as a result of their excessive physical characteristics. Health issues known as genetic illnesses are brought on by "flaws" in a person's genome.

Through artificial selection, several fruits and vegetables have been enhanced or even created. Selective breeding was very useful in creating broccoli, cauliflower, and cabbage from the wild mustard plant.

Thus, This is an example of selective breeding.

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Answer:

i think its a

Explanation:

Answer:

pH is a measure of how acidic/basic water is. The range goes from 0 to 14, with 7 being neutral.

HI has the least volume

Given

Gasses and molar mass

Required

The least volume

Solution

Ideal gas law

PV=nRT

V = (nRT)/P

n = mass : MW(Molar weight=molar mass)

[tex]\tt V=\dfrac{\dfrac{mass}{MW}RT }{P}\\\\V=\dfrac{mass.RT}{MW.P}[/tex]

so V is inversely proportional to MW(molar mass)

Because the values of P, R, T, and mass are the same, what matters is the value of the molar mass of each compound. The larger the molar mass the smaller the volume

From the available molar mass data, HI has the largest molar mass, so HI has the smallest volume

Answer: a

Explanation:

In a couplet one statement is agreeing and one is rejecting. Therefore, option A is correct.

A couplet is two lines of poetry that follow each other, particularly two lines that rhyme and are the same length.

Heroic couplets are similar to elegiac couplets. Heroic couplets are also usually closed and have their own meaning. They are frequently used in English epics and narrative poems.

A couplet is a unit of two lines of poetry that use the same or similar meter, rhyme, or are separated from other lines by a double line break. Here are some more important facts about Couplets are not required to be separate stanzas.

Thus, option A is correct.

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Answer:

20%

Explanation:

10.0 = 100%

8.00 = 80%

100-80= 20

Answer:

Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Answer:

Electromagnetic waves can be split into a range of frequencies. This is known as the electromagnetic spectrum. Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Explanation:

Answer:

The answers to your question are given below

Explanation:

The equation for the reaction is given below:

2KClO₃ —> 2KCl + 3O₂

The total number of each atoms present in the reactants and products can be obtained by doing a head count as illustrated below:

Reactants >>>>>> Number of atoms

Potassium (K) >>> 2 × 1 = 2

Chlorine (Cl) >>>> 2 × 1 = 2

Oxygen (O) >>>>> 2 × 3 = 6

Products >>>>>>> Number of atoms

Potassium (K) >>> 2 × 1 = 2

Chlorine (Cl) >>>> 2 × 1 = 2

Oxygen (O) >>>>> 3 × 2 = 6

Answer:

Opposite charges attract one another. The slight positive charges on the hydrogen atoms in a water molecule attract the slight negative charges on the oxygen atoms of other water molecules. This tiny force of attraction is called a hydrogen bond.

Considering the definition of hydrogen bond, the correct answer is option A: he Oxygen has a partial negative charge which attracts atoms and molecules that have a position or partial positive charge.

In hydrogen bonds, a molecule that presents hydrogen interacts with another that presents an atom with high electronegativity, such as oxygen, fluorine or nitrogen (O, F, N). In this way, between the hydrogen, which has a low electronegativity and the electronegative atom, an interaction is established, due to their opposite charges.

On the other hand, electronegativity is the ability of an atom to attract shared electrons in a covalent bond.

In the case of water, because oxygen is more electronegative than hydrogen, electrons, which have a negative charge, are more likely to be closer to the oxygen atom than to the hydrogen atom, which causes each hydrogen atom to have a positive charge is called a positive partial charge, and that of oxygen, a negative charge, since it has the electrons closer together.

In summary, the correct answer is option A: he Oxygen has a partial negative charge which attracts atoms and molecules that have a position or partial positive charge.

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Answer:

carbon dioxide I beleive.

Explanation:

dry ice is frozen liquid carbon dioxide and when it melts it gives off carbon dioxide gas.

The percent composition of Uranium in U308 = C. 81.03%

Given

X g of U

3.795 g of O

20.00 g of  U308

Required

The percent composition of Uranium

Solution

mass of Uranium in U308 :

= mass of U308 - mass of O

= 20 g - 3.795 g

= 16.205 g

The percent composition :

[tex]\tt \%U=\dfrac{mass~U}{mass~U308}\times 100\%[/tex]

%U = (mass U/mass U308) x 100%

%U= (16.205/20) x 100%

%U = 81.025≈81.03

Answer: Calculate the heat evolved (per mo SO2) for the reaction of sulfur with oxygen to form SO . Calculate the heat evolved from a reaction mixture of 13.4L SO at 1 ATM and 273K ... N-2 (g) + Os (g) → 2 NO (g) H = +180.6 kJ.

Explanation: I hoped that was helpful!