True or False: All metals have high melting points.

There are 1.204 x 10¹⁹ atoms O

The empirical formula is the smallest comparison of atoms of compound forming elements.  

A molecular formula is a formula that shows the number of atomic elements that make up a compound.  

1 mol of molecule Na₂C₂O₄ :

There are 4 mol of O in 1 mol of molecule Na₂C₂O₄

So for 5 x 10⁻⁶ mol Na₂C₂O₄ :

[tex]\tt mol~O=4\times 5.10^{-6}=2.10^{-5}[/tex]

1 mole = 6.02.10²³ particles , so number of atoms O :

[tex]\tt 2\times 10^{-5}\times 6.02\times 10^{23}=1.204\times 10^{19}[/tex]

The relative humidity on a starry summer night is determined as 91%.

The dry bulb depression temperature is calculated as follows;

ΔT = 19⁰C - 18⁰C   =  1⁰C

at dry bulb temperature of 18⁰C and depression temperature of 1⁰C, the relative humidity is determined as 91%.

Thus, the relative humidity on a starry summer night is determined as 91%.

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Answer:

focuses light on the retina

Explanation:

The sentences that probably comes from a work of classic literature are:

The great literary works of Greek, Roman, and other prehistoric civilizations are referred to as classical literature. Classical literature includes the writings of Homer, Ovid, and Sophocles. The phrase isn't just applicable to books. It can also incorporate other types of writing, such as epic, lyric, tragedy, comedy, and pastoral.

Classical literature enables us to take a profound plunge into the lives, worldviews, and mindsets of individuals we have never met, to travel to unfamiliar settings, and to comprehend eras we will never be able to experience ourselves.

Therefore, option C and D are correct.

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Given

the structure of the alkanes

Required

match the image to the name

Solution

Alkanes are saturated hydrocarbons with all of the carbon bonds being single bonds

General formula:

[tex]\large {\boxed {\bold {C_nH_2n + 2}}}[/tex]

If we look at the picture, we define the black atom as Carbon and the branch is Hydrogen

To determine the name of the alkane, all we have to do is count the number of Carbon atoms

Butane : C₄H₁₀ : 4 C atoms

Methane : CH₄ : 1 C atom

Ethane : C₂H₆ : 2 C atoms

Propane : C₃H₈ : 3 C atoms

Answer: I think it is D

Explanation:

There are 12 atoms of Oxygen, since 3 times 4 is 12.

Please mark brainliest!

Answer:

Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.

Inventions: Periodic table, Pyrocollodion

Explanation:

*Hope this helps*

Answer:

Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.

Inventions: Periodic table, Pyrocollodion

Explanation:

Answer:

Over time, the plant matter transforms from moist, low-carbon peat, to coal, All types of coal also contain sulfur, which, when burned, releases toxic air pollution. Sulfur All this coal comes from mines, which are either underground or run on diesel—a major source of air toxins, nitrogen oxide, and soot.

pH of the Sr(OH)₂ solution : 12.6

pH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.  

pH = - log [H⁺]  

Sr (OH) ₂ solution is a base with valence 2, so we determine the pOH from the OH ion concentration - which is expressed by pOH = - log [OH -]. After that we determine the pH value from the relationship:

[H⁺] [OH⁻] = Kw=10⁻¹⁴

pH + pOH = 14

Sr(OH)₂⇒Sr²⁺+2OH⁻

From equation [Sr(OH)₂] : [OH⁻]=1 : 2, so [OH⁻]=

[tex]\tt [OH^-]=2\times 2.10^{-2}=4.10^{-2}~M[/tex]

[tex]\tt pOH=-log[OH^-]\\\\pOH=-log~4.10^{-2}\\\\pOH=2-log~4\rightarrow 1.398 \\\\pH+pOH=14\\\\pH=14-1.398\\\\pH=12.6[/tex]

pH is the measurement of the concentration of hydrogen or hydronium ion in an aqueous solution. The pH of strontium hydroxide is 12.6.

The pH is the potential of hydrogen or the negative log of its concentration.

First, calculate the pOH of strontium hydroxide by:

[tex]\begin{aligned} \rm pOH &= \rm - log [OH ^{-}]\\\\&= \rm -log [4\times10^{-2}]\\\\&= 1.398\end{aligned}[/tex]

Now, calculate pH from pOH as:

[tex]\begin{aligned}\rm pH &= 14 - \rm pOH\\\\&= 14 - 1.398\\\\&= 12.6\end{aligned}[/tex]

Therefore, 12.6 is the pH of strontium hydroxide.

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Answer:

Decomposition reaction.

There's heating of solid Ammonium nitrate to form di nitrogen oxide and water

Answer:

BIPHASIC LIQUIDS are used ear cleaning, to softening the wax so that mild infections can be treated.

Explanation:

BIPHASIC LIQUIDS are liquids that contain two immiscible phases, one is suspension and the other is emulsion. In suspension, the finely solid are dispersed in a liquid or semi solidwhich is use for medicament

The emulsion consist of immiscible liquids, one is dispersed in globules.

They are used ear cleaning, to softening the wax so that mild infections can be treated.

Answer:

Solid

Explanation:

In solid there are strong intermolecular forces present as compared to liquid and gas. This is why solid are in more packed form as compared to liquid and gas. In liquid and gas intermolecular forces are week that's why molecules are away from each other and occupy more space.

Properties of gases:

Molecule of gases randomly move everywhere and occupy all available space.

Gases don't have definite volume and shape and take the shape and volume of container in which it present.

Their densities are very low as compared to the liquid and solids.

Gas molecules are at long distance from each other therefore by applying pressure gases can be compressed.

The very weak inter molecular forces are present between gas molecules.

Properties of Liquid:

Liquid have definite volume but don't have definite shape.

Their densities are high as compared to the gases but low as compared to the solids.

In liquid, molecules are close to each other and have greater inter molecular forces as compared to the gas molecules.

Properties of solids:

Solids have definite volume and shape.

In solids molecules are tightly pack and very close to each other.

Their melting and boiling point are every high.

The densities of solids are also very high as compared to the liquid and gas.

There are very strong inter molecular forces are present between solid molecules.

Answer:

A: Solid

Explanation:

Correct with Acellus

it is push i think to move the car

Answer:

Either A. Push or B.Pull because the truck is either pushing or pulling the car to move it. So it depends on if it's pushing or pulling the car.

Explanation:

Answer:

370,000 cal

Explanation:

Step 1: Given data

Step 2: Calculate the heat necessary to vaporize 685 g of water

Vaporization is the process in which a liquid converts to a gas, at a constant temperature. The heat required (Q) is:

Q = ΔH°vap × m

Q = 540 cal/g × 685 g

Q = 3.70 × 10⁵ cal

Answer:

4.63 mol

Explanation:

Step 1: Write the balanced complete combustion reaction of acetylene

2 C₂H₂(g) + 5 O₂(g) ⟶ 4 CO₂(g) + 2 H₂O(g)

Step 2: Establish the appropriate molar ratio

According to the balanced equation, the molar ratio of C₂H₂ to O₂ is 2:5.

Step 3: Calculate the number of moles of O₂ needed to react with 1.85 moles of C₂H₂

We will use the stoichiometric molar ratio.

1.85 mol C₂H₂ × (5 mol O₂/2 mol C₂H₂) = 4.63 mol O₂

Answer:

See explanation

Explanation:

The equation of the reaction is;

C 2 H 6 O(l)  +  3 O 2 (g)  → 2 CO 2 ( g )  +  3 H 2 O(l )

Next we have to determine the limiting reactant, this reactant gives the least number of moles of product.

Number of moles of C 2 H 6 O = mass/molar mass = 1.86g/ 46.07 g/mol = 0.04 mols

From the equation;

1 mol of ethanol yields 2 mols of CO2

0.04 moles of ethanol yields 0.04 * 2/1 = 0.08 mols of CO2

For water;

1 mol of ethanol yields 3 mols of water

0.04 moles of ethanol yields 3 * 0.04/1 = 0.12 mols of water

Also;

Number of moles of oxygen= 10g/32g/mol = 0.31 moles

3mols of O2 yields 2 moles of CO2

0.31 moles of O2 yields 0.31 * 2/3 = 0.21 moles of CO2

For water;

3 moles of O2 yields 3 moles of water

0.31 moles of O2 yields 0.31 * 3/3 = 0.31 moles of water

Hence ethanol is the limiting reactant.

From  PV=nRT

Volume of CO2 is;

V = nRT/P

V = 0.08 * 0.082 *298/1 = 1.95 L

Volume of water;

V = nRT/P

V= 0.12 * 0.082 * 298/1

V= 2.93 L

Total volume of gases after reaction = 1.95 L + 2.93 L = 4.88 L

liquid 1 and 2 have the same color and mass so the answer would be liquid 1 and 2

Explanation:

hope this is helpful

Answer:

FeCl3 + 3KOH → Fe(OH)3 + 3KCl

Explanation:

Answer:

C. potential energy

Explanation:

got 100 on edg

Answer:

See explanation

Explanation:

Now taking A, we can see that if we double the amount of A while keeping the amount of B constant, the rate of reaction doubles, hence we can write;

2^n = 2^1

hence n =1

For B, when the amount of B is doubled while keeping the amount of A constant, the rate of reaction increases eight times. Hence we can write;

2^n = 8

2^n = 2^3

n=3

Hence this reaction has an overall order of 1 + 3 = 4

So we can write;

rate =k[A] [B]^3

Answer:

radioactive decay

Explanation:

a study reveals that only about half of our planets internal heat stems from natural radioactivity the rest is primordial heat left over from when earth first coalesced from a hot ball of gas dust and other material

Answer:

Atoms of the same element have the same chemical properties. The only differences between atoms of the same element are the number of neutrons in the nucleus and the atomic weight of each isotope. false

Answer:

False

Explanation:

Different elements can have different properties, but not atoms of the same element

Answer:

The answer is 56

Explanation:

i need points

Answer:

a

Explanation:

all elemental metals are made up of only one type of element

Answer:

It is 1.

Explanation:

40567⁰ kkkkkkkkkkkkkkkkkkkkkkmeow

Explanation:

cuz I got a 100

Answer:

True

Explanation:

When a force acts on an object, the object may change shape by bending, stretching or compressing - or a combination of all three shape changes.

Answer:

A and D then I guess

Explanation:

sorry hope this helps!

The following objects will exert the greatest gravitational force on a box⇒ 8 kg mass

Gravity is a force that arises because of the attraction between objects with mass.  

The magnitude of this attraction is proportional to the mass of the object.  

The greater the mass of the object, the greater the gravitational force  

Relationships can both be stated in  

Newton's Gravity Law:  

[tex]\rm F=G.\dfrac{m_1.m_2}{r^2}[/tex]

with F = gravitational force,  

G = gravitational constant,  

m1, m2 = mass of object,  

r = distance between two objects.  

The distance-r and mass of the box(m₁) are the same, then the largest object's mass (m₂)exerts a large gravitational force, because the gravitational force is directly proportional to the mass of the two objects