I need help plz before 12:18 because my teacher did she was going to Fall me

Answer:

A chemical change has occurred

Explanation:

Given reaction expression:

      CaCO₃ →  CaO  +  CO₂

The reaction is a decomposition reaction in which a compound is dissociated into simple products.

The reason why the products have different properties than the reactants is because a chemical change has occurred.

The products of the decomposition of calcium carbonate have different properties because a chemical change has occured in the reaction to form new substances.

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Answer:

The answer is "Option b".

Explanation:

[tex]\to \text{number of moles} = \frac{\text{number of atoms}}{\text{avogadro number}}[/tex]

                               [tex]= \frac{7.0 \times 10^{19}}{6.0221 \times 10^{23}}\\\\= 1.16 \times 10^{-4} \ moles\\\\ =1.2 \times 10^{-4} \ moles[/tex]

[tex]\to \text{sample mass}= \text{number of moles} \times \text{molar mass}[/tex]

                        [tex]=1.16 \times 10^{-4}\times 58.9\\\\=0.00685 \\\\ = 6.85\ g[/tex]

Answer:

c, maybe d, and I think b.

Explanation:

Im sorry if wrong

Answer:

Its the first one. The cells are arranged for structure.

Explanation:

Animal cells do not need to maintain a shape since out bodies do it for us. Plant cells need something for structure.

Answer:

In the explanation

Explanation:

Divergent: When two plates are diverging from each other, meaning that the two plates are moving away from each other. Events that may occur include ridges or rifts.

Convergent: When two plates are moving towards each other.

If a continental plate and an oceanic plate are converging, the oceanic plate would slide underneath the continental plate since it is thinner. This would result in subduction, which means that part of the oceanic plate would hang underneath the continental plate, where magma can melt the hanging part.

If two continental plates are converging, the crash would result in mountains or volcanic activity. Magma could rise and rush from the crack. There would be a bump in these tectonic plates.

Transform: When two plates are sliding past each other. Earthquakes can occur when the plates are sliding. When an oceanic plate is involved, the movement of the plates could cause a tsunami as well. The water above the transform fault could rise, and grow bigger and bigger. The 2011 Japan Tsunami is a good example of this.

Hope this helps!

Answer: The energy of the infrared radiation is [tex]19.8\times 10^{-21}J[/tex]

Explanation:

The relationship between wavelength and energy of the wave follows the equation:

[tex]E=\frac{hc}{\lambda}[/tex]

E= energy

[tex]\lambda [/tex] = wavelength of the wave  =[tex]1.0\times 10^{-5}m[/tex]

h = Planck's constant  = [tex]6.626\times 10^{-34}Js[/tex]

c = speed of light = [tex]3\times 10^8m/s[/tex]

[tex]E=\frac{6.626\times 10^{-34}Js\times 3\times 10^8m/s}{1.0\times 10^{-5}m}[/tex]

[tex]E=19.8\times 10^{-21}J[/tex]

Thus energy of the infrared radiation is [tex]19.8\times 10^{-21}J[/tex]

The specific heat of the metal : 0.384 J/g° C,

and a metal with a specific heat of 0.384 is copper

The law of conservation of energy can be applied to heat changes, i.e. the heat received / absorbed is the same as the heat released  

Q in = Q out  

Q lost(metal) = Q gained(water)

Heat can be calculated using the formula:  

Q = mc∆T  

Q = heat, J  

m = mass, g  

c = specific heat, joules / g ° C  

∆T = temperature difference, ° C / K  

[tex]\tt Q~metal=Q~water\\\\8.5\times c\times (100-23.2)=50\times 4.18\times(23.2-22)\\\\652.8\times c=250.8\Rightarrow c=\dfrac{250.8}{652.8}=0.384~J/g^oC[/tex]

Answer:

True

True

Temperature

Explanation:

Answer:

hydrogenation

Explanation:

Liquid vegetable oils are converted to solid fats such as margarine by a process known as hydrogenation.

Commercial production of margarine requires the hydrogenation of liquid oil at a relatively high temperature and pressure and in the presence of a catalyst. During the process, a solid catalyst (usually, nickel) is added to a preheated liquid vegetable oil before the dispersion of the hydrogen gas. The polyunsaturated vegetable oil, thus, becomes saturated or partially saturated in the process. The quality of the final product depends on the degree of hydrogenation or saturation.

The process of hydrogenation turns liquid vegetable oils into solid fats like margarine. therefore, the correct option is option B.

Unsaturated molecules undergo a chemical reaction called hydrogenation in which hydrogen gas is added. Unsaturated fats and oils are frequently transformed into saturated forms, which makes them more stable and solid at room temperature. Margarine, shortenings, and other solid fats are frequently made using this method. In order to increase stability, decrease reactivity, or change the physical and chemical properties of organic compounds, hydrogenation can also be employed to diminish or eliminate double or triple bonds in such molecules.

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Your question is incomplete but most probably your full question was,  

Answer:

Avogadro's law (sometimes referred to as Avogadro's hypothesis or Avogadro's principle) is an experimental gas law relating the volume of a gas to the amount of substance of gas present.[1] The law is a specific case of the ideal gas law. A modern statement is:

Avogadro's law states that "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules."[1]

For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant.

The law is named after Amedeo Avogadro who, in 1812,[2][3] hypothesized that two given samples of an ideal gas, of the same volume and at the same temperature and pressure, contain the same number of molecules. As an example, equal volumes of molecular hydrogen and nitrogen contain the same number of molecules when they are at the same temperature and pressure, and observe ideal gas behavior. In practice, real gases show small deviations from the ideal behavior and the law holds only approximately, but is still a useful approximation for scientists.

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Answer:

Cooling causes contraction and shifting of the fluid particles in the lithosphere.

Answer:

The 2 answer

Explanation:

Answer:

Option C 28 Proton 31 neutron 26 elecrtons

Explanation:

Answer:

Density = M/V

so 3.81/14.3 .266g/ml

Explanation:

Answer:

Noble Gases

Explanation:

Noble gases are very unreactive because they already have a full valence shell and therefore, do not need to bond.

Answer:

Noble gases

Explanation:

The molar mass of gas = 206.36 g/mol

In general, the gas equation can be written

[tex]\large{\boxed{\bold{PV=nRT}}}[/tex]

where

P = pressure, atm

V = volume, liter

n = number of moles

R = gas constant = 0.082 l.atm / mol K

T = temperature, Kelvin

mass (m)= 2.89 g

volume(V) = 346 ml = 0.346 L

T = 28.3 C + 273 = 301.3 K

P = 760 mmHg=1 atm

The molar mass (M) :

[tex]\tt PV=\dfrac{m}{M}RT\\\\M=\dfrac{mRT}{PV}\\\\M=\dfrac{2.89\times 0.082\times 301.3}{1\times 0.346}\\\\M=206.36~g/mol[/tex]

Answer:

P₂ = 2.60 atm

Explanation:

Given data:

Initial pressure = 2.38 atm

Initial temperature = 25.0 °C

Final pressure = ?

Final temperature = 52.78°C

Solution:

Initial temperature = 25.0 °C (25.0+273 = 298 K)

Final temperature = 52.78°C (52.78+273 = 325.78 K)

According to Gay-Lussac Law,

The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.

Mathematical relationship:

P₁/T₁ = P₂/T₂

Now we will put the values in formula:

2.38 atm / 298 K = P₂/325.78 K

P₂ = 2.38 atm × 325.78 K  / 298 K

P₂ = 775.35 atm. K /293 K

P₂ = 2.60 atm

Answer:

Barium chloride + Sodium phosphate    →   barium phosphate + sodium chloride

Explanation:

Double replacement:

It is the reaction in which two compound exchange their ions and form new compounds.

AB + CD → AC +BD

Chemical equation:

BaCl₂ + Na₃PO₄         →     Ba₃(PO₄)₂ + NaCl

Balanced chemical equation:

3BaCl₂ + 2Na₃PO₄         →     Ba₃(PO₄)₂ + 6NaCl

The cation and anion of both reactants are exchanged with each other.

Ba²⁺ react with PO₄³⁻ and form Ba₃(PO₄)₂ while Cl⁻ react with Na⁺ and form sodium chloride.  

Molecular equation:

Barium chloride + Sodium phosphate    →   barium phosphate + sodium chloride

Answer:

Answer:

Natural gas

Explanation:

Natural gas is a gaseous fossil fuel produced from organic matter that is used to heat homes and cook food.

Natural gas is one of the most volatile part of hydrocarbons that exist together with fossil fuel.

Answer:

16.86%

Explanation:

Na3N is sodium nitride.

% of N = mass of N/ molar mass of Na3N *100

% of N = 14/83*100= 16.86%

The percent composition of nitrogen in sodium nitride is 16.86%

Sodium nitride is an inorganic compound that is used in preservatives and antidote for cyanide poisoning.

The molar mass of Na3N is 83 M

The mass of Na3N is 14 g

[tex]% \;of \;N = \dfrac{mass of N}{ molar mass of Na3N } \times 100[/tex]

[tex]\% \;of \;N = \dfrac{mass\; of \;N}{molar\; mass\; of\; Na3N} \times 100\\\\\\\% \;of \;N = \dfrac{14}{83} \times 100 = 16.86\%[/tex]

Thus, the  percent composition of nitrogen in sodium nitride is 16.86%.

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Answer:

1.18 × 10²⁴ particles Mg

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

47.7 g Mg

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Mg - 24.31 g/mol

Step 3: Convert

[tex]47.7 \ g \ Mg(\frac{1 \ mol \ Mg}{24.31 \ g \ Mg} )(\frac{6.022 \cdot 10^{23} \ particles \ Mg}{1 \ mol \ Mg} )[/tex] = 1.18161 × 10²⁴ particles Mg

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

1.18161 × 10²⁴ particles Mg ≈ 1.18 × 10²⁴ particles Mg

Answer:

1.08 g of water

Explanation:

The balanced chemical equation for the reaction of combustion of methane (CH₄) is the following:

CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(g)

According to the equation, 1 mol of CH₄ reacts with 2 moles of O₂. We convert from mol to grams by using the molar masses:

1 mol CH₄ = (1 x 12 g/mol) + (4 x 1 g/mol) = 16 g

2 mol O₂ = 2 x (2 x 16 g/mol) = 64 g

2 mol H₂O = 2 x ((2 x 1 g/mol) + 16 g/mol)= 36 g

From the masses of reactants (CH₄ and O₂), we can see that the stoichiometric ratio is 64 g O₂/16 g CH₄ = 4.

First, we have to identify which reactant is the limiting reactant. We can compare the stoichiometric ratio with the actual reactants ratio (the masses of reactants we have):

1.92 g O₂/0.80 g CH₄ = 2.4

As 4>2.4, we can conclude that O₂ is the limiting reactant.

Now, we consider the stoichiometric ratio between the limiting reactant (64 g O₂) and the product we have to calculate (36 g H₂O), and we multiply the ratio by the actual mass of O₂:

1.92 g O₂ x 36 g H₂O/64 g O₂ = 1.08 g

Therefore, 1.08 g of H₂O will be produced by the chemical reaction of 0.80 g of methane with 1.92 g of oxygen.

Answer:

☑ Friction between an object and chair

☐ The force between two magnets

☐ The force between two charged particles

☐ The gravitational pull of a planet

Answer:

are called Compounds

Answer:

Compouds

think of a group

an they are alll combined

also "compounds" com-bind = com-POUNDS

Make's sense now?

Answer:

Explanation:

The height of the object can be found by using the formula

[tex]h = \frac{p}{mg } \\ [/tex]

where

p is the potential energy

m is the mass

h is the height

g is the acceleration due to gravity which is 10 m/s²

From the question we have

[tex]h = \frac{23048}{39 \times 10} = \frac{23048}{390} \\ = 59.0974...[/tex]

We have the final answer as

Hope this helps you

Answer:

Q8) True

Q9) First ionization energy

Q10) A metal oxide

Explanation:

One of the properties of group one elements (alkali metals) is that they combine with water to form basic solutions. E.g 2Na(s)+2H2O(l)→2NaOH(aq)+H2​(g).

An inverse relationship exists between the distance of the outermost electron in the atom from the nucleus and the first ionization energy. As the distance between the outermost electron and the nucleus in group 17 elements increases, their first ionization energies decreases accordingly.

Group 1 elements react with oxygen to yield the corresponding metal oxides. E.g  4 Na + O2 --> 2 Na2O