Determine whether the statement is true or false, and why. "If a theory becomes supported by evidence, it can become a law."

A. False, it should read, "A theory and a hypothesis are already equally supported by evidence, but they have different functions."

B. False, it should read, "If a theory becomes supported by evidence, it can become a hypothesis."

C. True

D. False, it should read, "A theory and a law are already both supported by evidence and are equal, but they have different functions."

Answer:

Atoms contain the same amount protons and neutrons, and their charges cancel out.

Explanation:

Answer via Educere/ Founder's Education

Atoms contain positive and negative charges, the overall charge on an atom neutral because Atoms contain the same amount of protons and electrons, and their charges cancel out.Hence, Option (A) is correct

An atom is the smallest unit of ordinary matter that forms a chemical element.

Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms.

Atoms are extremely small, typically around 100 picometers across.

An atom consists of a positively charged nucleus, surrounded by one or more negatively charged particles called electrons.

The positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral.Hence, Option (A) is correct

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THIS IS THE COMPLETE QUESTION BELOW

46.9 gram sample of a substance has a volume of about 3.5 centimeters3. It is solid at a room temperature of 23ºC. Out of the four substances whose properties are given, which is the most likely identity of this substance?

Substance Density (g/cm3) Melting Point (°C) Boiling Point (°C)

molybdenum 10.28 2,623 4,639

mercury 13.53 -39 357

hafnium 13.31 2,233 4,603

lead 11.34 327 1,749

A.

molybdenum

B.

mercury

C.

hafnium

D.

lead

Answer :

The correct option is OPTION C.

(C) Hafnium

Explanation;:

We were given the mass of substance as (m) = 46.9 g

The Volume of substance as (V) = 3.5 Cm^3

But we know Density of substance.= Mass/it's Volume

Then Density=46.9/3.5

=13.4g/Cm^3

From the questionthe given substance is solid at room temperature, and let us take Mercury as an example , Mercury is liquid at room temperature. ThenMercury cannot be the answer.

Base on the determined density which is 13.4 and the density of Hafnium also is 13.31 g/cm3 and it is solid at room temperature. Therefore, Hafnium is the only likely element here.

Answer:

A. 35

B. 7

C. halogênios

Explanation:

Aqui, para responder a essa pergunta, precisaremos conhecer o elemento particular em questão.

..... 4s ^ 2 3d ^ 10 4p ^ 5 significa que está a cinco elétrons da configuração eletrônica do último elemento na primeira camada dos metais pesados.

O último elemento da 1ª série do elemento de transição é o zinco, portanto, como está a apenas 5 elementos de distância, o átomo de que estamos falando é o átomo de Bromo de Bromo.

A. O zinco tem um número atômico 30 e como o bromo está a 5 elementos de distância, seu número atômico é 35

B. Uma vez que pertence ao grupo halogênio, tem 7 elétrons de valência como o resto da família

C. Pertence à família dos halogênios

Answer:

it explain odds of finding the position of an electron.

Answer:

The correct answer is 187.7 J/Jg.

Explanation:

The formula for finding the specific heat of fusion is,  

Specific heat of fusion = Q/m

Here Q is the heat energy added, signified in kJ, and m is the mass of the object in kg.  

Based on the given information, the heat energy added or Q is 869 kJ and the mass of the ice is 4.6 Kg

Now putting the values in the formula we get,  

Specific heat of fusion = Q/m

Specific heat of fusion = 863 kJ / 4.6 Kg = 187.7 J/Kg

Explanation:

HOPE IT will be right..

Answer:

A. To simplify the design of the rocket.

Explanation:

3 stage rockets require huge amounts of fuel when launched in order to last the entire voyage.

As the rocket flies, some compartments may be detached and fall away from the rocket, decreasing its mass (eliminating B, as it is reasonable). This is done so that the rocket only carries necessary mass, which doesn't include the used up rocket parts (eliminating D, as it is reasonable). When the rocket finally reaches space, the decrease in gravity means less thrust is needed, which is an important thing to take note of while designing the rocket (eliminating C, as it is reasonable).

A three stage rocket is very complex and has many features and mechanisms that are complicated to add and deal with. Giving a rocket, three stages is not a simplification, so A is the answer.

A. To simplify the design of the rocket

At supersonic speeds (faster than the velocity of sound), the great shape is a narrower and sharper point. Rockets with a bigger diameter have greater drag because there's greater air being driven out of the manner.

Designing A Rocket In Six Easy Steps is given below

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Answer:

7 significant numbers

Answer:

Explanation:

To solve the question above we must first find the pH of the solution using the formula

pH + pOH = 14

pOH = 3.1

So we have

pH + 3.1 = 14

pH = 14 - 3.1

pH = 10.9

Since it's pH is 10.9 the solution is a basic solution since it's pH lies in the basic region.

Hope this helps you

Answer:

Iodine

Explanation:

Hope this helps. Think about me, when giving out brainiest.

Answer:

Explanation:

given

volume=1.85 d m^3

T=27 degree C=27+273 k=300 k

P=750 mmHg

mass of zinc=?

we know that PV=nRT

n=m/M

PV=mRT/M

M for zinc=65.4

PVM=mRT

m=PVM/RT

m=750*1.85*65.4/0.0821*300

m=90742.5/24.63

m=3684

hope this will help u

Answer:

Explanation:

Absorption of digested food takes place in the small intestine.

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Answer:

Absorption of digested food takes place in the small intestine.

Explanation:

Answer:

The correct option is;

D. Manganese (Mn)

Explanation:

Manganese is very brittle, hard, iron like silvery-gray metal, that is difficult to melt. In air, Manganese slowly disintegrate in a similar manner to iron rusting in water

Manganese and iron have similar chemical and physical properties however manganese is more harder and more brittle than iron

A brittle material is one that easily breaks without deforming elastically

Therefore, manganese, due to its very iron like appearance and brittle nature will be suitable to replace the metal wall and crumble easily when the actor hits it.

Answer:

The answer to this question is approximately equal to 1.6 ×

[tex] 1.6 \times {10}^{23} atom \: o[/tex]

Answer:

Those aspects which are something a village needs are specified beneath.

Explanation:

Answer:

Explanation:

Let the no in the ones place be x

And the no in the tens place be 10 - x

Original no = 10 ( 10 - x ) + x

= 100 - 10x + x

= 100 - 9x

Reversed no = 10 - x + 10 ( x )

= 10 - x + 10 x

10 + 9x

According to the question,

the new number formed exceeds the originals numbers by 54.

10 + 9x = 100 - 9x + 54

10 + 9x = 154 - 9x

By transposing,

9x + 9x = 154 - 10

18 x = 144

x = 144 / 18

x = 8

∴ Digit in ones place = x = 8

Digit in tens place = 10 - x = 10 - 8 = 2

So the number = 28

( You can also recheck it by adding the ones and tens digit

8 + 2 = 10

In the question, the sum of ones and tens digit in ten )

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Answer:

Two of the three salts are soluble.

One of the three salts is soluble.

Explanation:

One or two of the three salts would be soluble in water depending on if the water is cold or hot.

According to the solubility rules of chloride salts, all chlorides are soluble in cold water except for those of silver (Ag), lead (Pb), and mercury (I) (Hg).

This thus means that both AgCl and [tex]PbCl_2[/tex] would be insoluble in cold water while LiCl would be soluble.

[tex]PbCl_2[/tex] is, however soluble in hot water.

Hence, in cold water, one of the three salts (LiCl) would be soluble, while in hot water, two of the three salts (LiCl and [tex]PbCl_2[/tex]) would be soluble.

Answer:

c. 1.0 mole C5H5N and 1.5 mole C5H5NHCl

Explanation:

We can determine pH of a buffer using H-H equation:

pH = pKa + log [A⁻] / [HA]

Where [A⁻] is concentration of conjugate base and [HA] concentration of weak acid. These concentrations can be computed as moles of each species.

We need to determine pKa of both NH₃ and C₅H₅N buffers, thus:

pKb = -log Kb

NH₃ pKb = -log 1.8x10⁻⁵ = 4.74

C₅H₅N pKb = -log 1.7x10⁻⁹ = 8.77

And pKa = 14 - pKb:

NH₃ pKa = 14 - 4.74 = 9.26

C₅H₅N pKb = 14 - 8.77 = 5.23

A buffer works only under pH's between pKa-1 and pKa + 1. As pKa NH₃ buffer is 9.23 is not possible to produce a buffer with pH 5.05 for this system.

Thus, we only will compute the buffers made with C₅H₅N:

c. 1.0 mole C5H5N (Weak base) and 1.5 mole C5H5NHCl (Conjugate acid)

pH = pKa + log [A⁻] / [HA]

pH = 5.23+ log [1.0 moles] / 1.5 moles]

d. 1.5 mole C5H5N and 1.0 mole C5H5NHCl

pH = pKa + log [A⁻] / [HA]

pH = 5.23+ log [1.5 moles] / 1.0 moles]

Right solution is:

Answer:

a. the 3 represents the principal energy level

Explanation:

3 is the principal energy level. The p is the sublevel. 4 is the possible occupying electron.

Answer:

Proteins

Explanation:

Amino acids act as monomers (a single unit used to form polymers) , the polymer will be a long chain of individual amino acids. An amino acid chain forms a protein. These proteins are also known as peptides.

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Due to drought, the production of corn decreases and shortage of it occurs.

Yes, commodities in one sector should be used  in another sector because scientist invented methods in which one commodity is used in several sectors for the production of new products.

Corn was used for the production of ethanol which causes the shortage of corn that was available to consumers during and  after the drought condition of 2012 so we can conclude that due to drought, the production of corn decreases and shortage of it occurs.

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Molarity= No of moles of solute * 1000 / vol solution in ml

No of moles= Given mass / Molar mass

Given Mass of solute (H2O2)= 10g

Molar mass of H2O2=34gmol^-1

No of moles= 10/34= 0.294 moles

Volume of solution=50ml

Molarity =   0.294*1000 / 50

Molarity = 5.8M

Answer:

CaF2

Explanation:

Calcium fluoride is a solid formed by the chemical combination of Calcium (Ca) and Fluorine (F). Two molecules of fluorine (F2) and one molecule of Calcium (Ca) are needed to form the Calcium Fluoride molecule.

An ionic bond is formed between the Calcium and Fluorine atoms i.e. electrons are transferred from calcium atoms to fluorine atoms. The calcium ion is a cation with formula; Ca2+ while fluorine is an anion with formula; F-. Hence, it takes two molecules of Fluorine ion (F-) to form a relatively stable and neutral molecule with 1 molecule of Calcium ion (Ca2+).

Answer:

In chemistry the reactivity series is an empirical, calculated, and structurally analytical progression of a series of metals, arranged by their "reactivity" from highest to the lowest.

Answer:

In a reactivity series, the most reactive element is placed at the top and the least reactive element at the bottom. More reactive metals have a greater tendency to lose electrons and form positive ions.

A reactivity series of metals could include any elements. For example,

A list of elements from most reactive to least reactive: potassium, sodium, lithium, calcium, magnesium, aluminum, zinc, iron, copper, silver, and gold.

A good way to remember the order of a reactivity series of metals is to use the first letter of each one to make up a silly sentence. For example, People Say Little Children Make A Zebra Ill Constantly Sniffing Giraffes.

Observations of the way that these elements react with water, acids, and steam enable us to put them into this series.

The tables show how the elements react with water and dilute acids:

Element Reaction with water

Potassium Violently

Sodium Very quickly

Lithium Quickly

Calcium More slowly

Element Reaction with dilute acids

Calcium Very quickly

Magnesium Quickly

Zinc More slowly

Iron More slowly than zinc

Copper Very slowly

Silver Barely reacts

Gold Does not react

Note that aluminum can be difficult to place in the correct position in the reactivity series during these experiments. This is because its protective aluminum oxide layer makes it appear to be less reactive than it really is. When this layer is removed, the observations are more reliable.

Non-metals in the reactivity series

It is useful to place carbon and hydrogen into the reactivity series because these elements can be used to extract metals.

Here is the reactivity series including carbon and hydrogen:

A list of elements from most reactive to least reactive: potassium, sodium, lithium, calcium, magnesium, aluminum, carbon, zinc, iron, hydrogen, copper, silver, and gold.

Note that zinc and iron can be displaced from their oxides using carbon but not using hydrogen. However, copper can be extracted using carbon or hydrogen. Displacement reactions of metal oxides

A more reactive metal will displace a less reactive metal from a compound. The thermite reaction is a good example of this. It is used to produce white-hot molten (liquid) iron in remote locations for welding. A lot of heat is needed to start the reaction, but then it releases an incredible amount of heat, enough to melt the iron.

aluminium + iron(III) oxide → iron + aluminium oxide

2Al + Fe2O3 → 2Fe + Al2O3

Because aluminum is more reactive than iron, it displaces iron from iron(III) oxide. The aluminum removes oxygen from the iron(III) oxide:

iron is reduced

aluminum is oxidized

Reactions between metals and metal oxides allow us to put a selection of metals into a reactivity series. Using metals A, B, and C:

Metal A Metal B Metal C

A oxide X Displaces A Displaces A

B oxide No reaction X No reaction

C oxide No reaction Displaces C X

Metal A cannot displace either B or C - so it must be the least reactive and be at the bottom of this reactivity series.

Metal B displaces both A and C - so it must be the most reactive and be at the top of this reactivity series.

Metal C displaces A but cannot displace B - so it must be more reactive than A but less reactive than B, and be in between them in this reactivity series.

In general, the greater the difference in reactivity between two metals in a displacement reaction, the greater the amount of energy released.

Aluminum is much higher than iron in the reactivity series, so the thermite reaction releases a lot of energy. Magnesium is very high in the reactivity series, and copper is very low - so the reaction between magnesium and copper oxide is more violent.

Therefore, the order is:

A list of letters from most reactive to least reactive: B, C and A,

Displacement reactions of solutions

A more reactive metal will displace a less reactive metal from a solution of one of its salts. For example:

magnesium + copper(II) sulfate → copper + magnesium sulfate

Mg(s) + CuSO4(aq) → Cu(s) + MgSO4(aq)

In this reaction, the blue color of the copper(II) sulfate fades as it is used up (magnesium sulfate solution is colorless). We would also see copper metal forming.

Reactions between metals and solutions of metal salts allow us to put a selection of metals into a reactivity series. Using metals J, K, and L:

Metal J Metal K Metal L

J sulfate X No reaction No reaction

K sulfate Displaces K X Displaces K

L sulfate Displaces L No reaction X

Metal J displaces both K and L - so it must be the most reactive and be at the top of this reactivity series.

Metal K cannot displace either J or L - so it must be the least reactive and be at the bottom of this reactivity series.

Metal L displaces K but cannot displace J - so it must be more reactive than K but less reactive than J, and be in between them in this reactivity series.

- sorry I'm late and it's is long -_-||

Answer: Option (A) is the correct answer.

Explanation:

An atom who has seven valence electrons in its ground state will have the following electronic configuration in its sub shells as 2, 7.

Thus, there will be in total 9 electrons and it is known that fluorine has atomic number 9.

Whereas sodium has 2, 8, 1 electrons in its sub-shell.

Calcium has 2, 8, 8, 2 electrons in its sub-shell and oxygen has 2, 6 electrons in its sub-shell.

Thus, we can conclude that out of the given options, fluorine is the element whose atom in the ground state has seven valence electrons.

Answer:

Wavelength (λ) = 1.875 × 10⁻⁶ m

Explanation:

Given:

Energy (e) =  1.06 × 10⁻¹⁹ J

Find:

Wavelength (λ) = ?

Computation:

e = hc / λ

λ = hc / e

where c = 3 × 10⁸

Planck's constant (h) = 6.625 × 10⁻³⁴

So,

Wavelength (λ) = (6.625 × 10⁻³⁴)(3 × 10⁸) / (1.06 × 10⁻¹⁹)

1. Wavelength (λ) = 1.875 × 10⁻⁶ m

2. Given n = 4 to n = 3 both are integer not fraction so, electron is quantize

Answer:

Cells are the "building blocks for all living things." Without cells, we couldn't survive. Cells do many important things. Some of the things they can do are taking in food nutrients, frame our bodies, and change the food nutrients into energy.

Answer:

C

Explanation:

The ions are first accelerated electrically, and then bended magnetically to sort them and record them.

Answer:

physical

Explanation:

The change is physical.

A physical change involves a reversible change to the physical properties of substances, whereas a chemical change involves an irreversible change to the chemical properties of substances through a chemical reaction.

The dissolution of common salt is a physical change because the common salt can be retrieved by evaporating off the water. This is what was manifested by the deposition of common salt crystals on the wick.