pls help what’s the answer?

Answer:

Gold is element 79 and its symbol is Au.

Answer:

²³⁸₉₂U has 146 neutrons

Explanation:

To know which option is correct, we shall determine the number of neutrons in each case. This can be obtained as follow:

For ²⁴₁₂Mg:

Mass number (A) = 24

Proton number (P) = 12

Neutron number (N) =?

A = P + N

24 = 12 + N

Collect like terms

N = 24 – 12

N = 12

Thus, there are 12 neutrons in ²⁴₁₂Mg

For ⁷⁵₃₃As:

Mass number (A) = 75

Proton number (P) = 33

Neutron number (N) =?

A = P + N

75 = 33 + N

Collect like terms

N = 75 – 33

N = 42

Thus, there are 42 neutrons in ⁷⁵₃₃As

For ¹⁹₉F:

Mass number (A) = 19

Proton number (P) = 9

Neutron number (N) =?

A = P + N

19 = 9 + N

Collect like terms

N = 19 – 9

N = 10

Thus, there are 10 neutrons in ¹⁹₉F.

For ²³⁸₉₂U:

Mass number (A) = 238

Proton number (P) = 92

Neutron number (N) =?

A = P + N

238 = 92 + N

Collect like terms

N = 238 – 92

N = 146

Thus, there are 146 neutrons in ²³⁸₉₂U

Considering the options and the illustration made above, Only ²³⁸₉₂U has the correct number of neutrons written along side.

Answer:

Net equation: Cu + 2Ag+  ⇒ 2Ag + Cu2+

Explanation:

Cu + 2N03- + 2Ag+ ⇒ 2Ag + 2NO3- + Cu2+

The 2NO3- cancel out since they're spectator ions

∴ Cu + 2Ag+ ⇒ 2Ag + Cu2+

Half equations are:

Cu ⇒ Cu2+

2Ag+ ⇒ 2Ag

Balancing both sides of each equation with electrons will lead back to the Net equation.

Answer:

H2 would have a coefficient of 2.

Explanation:

According to the balanced chemical equation, the coefficient of hydrogen is 4.

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .

The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.

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Answer:

The physical properties of a solution are different from those of the pure solvent. ... Colligative properties are those physical properties of solutions of nonvolatile solutes that depend only on the number of particles present in a given amount of solution, not on the nature of those particles.

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Answer:

phylogenic trees/phylogeny

Explanation:

the evolutionary history and relationship of an organism or group of organisms is called its phylogeny

Answer: 35.6 g/mol

Explanation: I guessed and got it correct

The molar volume of any gas behaving ideally at STP is 22.414 L. The molar mass of the gas at STP is 35.59 g.

The molar mass of a substance is defined as the mass of one mole of molecules. In other words one gram molecular mass of a substance is same to its molar mass in g mol⁻¹.

The molar mass of a substance can be obtained by adding the atomic masses of each elements.  At 0°C and 1 atm, 1 mole of any gas behaving ideally occupies a volume of 22.414 L.

Here 5.00 L of the gas at STP has a mass of 7.94. Then the molar mass of 22.414 liters of the gas can be calculated as:

7.94 × 22.414/5.00 = 35.59 g.

Thus the molar mass of the gas is 35.59 g.

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Answer:

Id want to know how the nucleus looks like upclose, is it really that neutrons and protons are bond together, or are they just sticking in together. I'd also wanna look at electrons, or even possible hold them so that i can see the mass it really has

Explanation:

Explanation:

Partial pressure of a gas is the product of the mole fraction of that gas, which is the ratio of the no. of moles of the gas to the total no. of moles, and the total pressure.

total no. of moles=0.74+0.25=0.99 mol

mole fraction of N2=0.74/0.99=0.7475

mole fraction of O2=0.25/0.99=0.2525

total pressure=1.7+4.7=6.4 atm

partial pressure of N2=0.7475×6.4=4.784 atm

partial pressure of O2=0.2525×6.4=1.616 atm

Answer:

0.880 (0.88039867109 to be exact)

Explanation:

To convert from molecules to moles, simply divide by Avogadro's number which is 6.02 x 10^23

So, 5.30x10^23/6.02x10^23 = 0.880

Answer:

The empirical and molecular formula because the ratio is 2:1 and there is 2 hydrogen atoms and 1 oxygen atom.

Hope this helps!

1) single replacement

2) Zn + 2HCl -----> ZnCl + H

equation is already balanced

Answer:

True

Explanation:

It means the reaction is occuring.

Answer:

28.23 g NH₃

Explanation:

The balanced chemical equation is:

N₂(g) + 3 H₂(g) → 2 NH₃(g)

Thus, 1 mol of N₂ reacts with 2 moles of H₂ to produce 2 moles of NH₃. We convert the moles to mass (in grams) by using the molecular weight (MW) of each compound:

MW(N₂) = 2 x 14 g/mol = 28 g/mol

mass N₂= 1 mol x 28 g/mol = 28 g

MW(H₂) = 2 x 1 g/mol = 2 g/mol

mass H₂ = 3 mol x 2 g/mol = 6 g

MW(NH₃) = 14 g/mol + (3 x 1 g/mol) = 17 g/mol

mass NH₃= 2 moles x 17 g/mol = 34 g

Now, we have to figure out which is the limiting reactant. For this, we know that the stoichiometric ratio is 28 g N₂/6 g H₂. If we have 36.85 g of H₂, we need the following mass of N₂:

36.85 g H₂ x 28 g N₂/6 g H₂ = 171.97 g N₂

We have 23.15 g N₂ and we need 171.97 g. So, we have lesser N₂ than we need. Thus, the limiting reactant is N₂.

Now, we calculate the product (NH₃) by using the stoichiometric ratio 34 g NH₃/28 g N₂, with the mass of N₂ we have:

23.25 g N₂ x 34 g NH₃/28 g N₂ = 28.23 g NH₃

Therefore, the maximum amount of NH₃ that can be produced is 28.23 grams.

Answer:

Explanation:

Polar side chains tend to be present on the surface of a protein where they can interact with the aqueous environment found in cells. On the other hand, non-polar amino acids tend to reside within the center of the protein where they can interact with similar non-polar neighbors.

Answer:

answer below:

Explanation:

1) 4 Al + 3 O2 --> 2Al2O3.

2) Al mol= 28/27 = 1.037mol

O mol= 45/16 = 2.812mol

Al : O

4 : 2

x : 2.812

cross multiply

4 x 2.812/2  = 5.624 mol of Al

Al is limiting reactant

3) 28/5.246 = 5.34product can be formed (not that much sure)

4) 45/ 0.5185 = 86.79

86.79 - 5.34 = 81.45g

5) 50 / 81.45 x 100 = 61.39% ( i guess)

i hope this hleps you

Answer:

Wdym?

Explanation:

I don't understand this question

Answer:

gatekeeper

Explanation:

Answer:

Is this a general question or is there supposed to be a picture

Explanation:

Explanation:

Technically, the ice cube melts because the water cools down. This may sound ridiculous at first, but you must consider the fact that the ice melts because it has drawn "heat" (energy) from its surroundings. The "surroundings" being the air and water that surround it (but the water's more important since it's a better conductor of thermal energy).

The surrounding air looses energy while the ice in the glass gains energy.

We know that thermal energy is transferred from a hotter body to a cooler body. If we look as the glass, we will notice that the surrounding air has a greater energy compared to the contents of the glass. The surrounding air looses this energy resulting in the condensation of water vapor in air around the glass.

Similarly, the ice in the glass gains energy and melts. A change of state occurs from solid to liquid as a result of the energy absorbed from the surrounding air.

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Answer:

PCl3

Explanation:

The molecular formular of a compound shows the exact number of atoms of elements present in the compound. In this illustration, there is one atom of P and 3 atoms of Cl.

The formular is given as; PCl3

Answer:

PCl³

Explanation:

because there are 1 phosphorus atom and 2 chlorine atom.

Answer:

propylcyclopentane

Explanation:

The rest Are swiggly lines and more than 5 sides

The organic compounds which consist of single bonded carbon and hydrogen atoms are called alkanes. They are also called the saturated hydrocarbons. Here the given alkane is propylcyclopentane. The correct option is A.

The propylcyclopentane is an alkane which is the simplest family of hydrocarbons. It is a cyclic hydrocarbon which acts as the major component of gasoline and it is also used in the manufacture of synthetic resins and rubber adhesives.

The propylcyclopentane is an important cycloalkane which contains five carbon atoms bonded to two hydrogen atoms above and below the plane. It appears as a clear colourless liquid with a petroleum like odor. It is less dense than water and it is insoluble in water.

Propylcyclopentane is a member of cyclopentanes, a cycloalkane and a volatile organic compound. Its molecular formula is C₈H₁₆. It can also be called as 1 - Cyclopentylpropane.

Thus the correct option is A.

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total pressure=248+707+518=1473mmHg

partial pressure=total pressure×mole fraction

mole fraction of N2

=partial pressure of N2/total pressure

=707mmHg/1473mmHg

=0.4800