How do stars contribute to the elements inside you?

Answer:

A system absorbs more energy than it releases and has a positive AH  

Explanation:

Answer:

Explanation:

Endothermic (endo = into + thermic = heat) means that heat energy is going into a system.

The products will have more energy than the reactants and ΔH will be positive.

A is wrong, because ΔH is positive.

C and D are wrong, because the system absorbs more energy than it releases.

Answer:

nickel 48.1063%

Phosphorus 16.9245%

Oxygen 34.9692%

The percent composition of each element like nitrogen, oxygen and phosphorous in Ni₃(PO₄)₂ are 48.03%, 34.97% and 16.93% respectively.

Percent composition of any element present in any compound will be calculated as:
% comosition = (Mass of element / Mass of compound)×100%

Mass of Ni₃(PO₄)₂ compound = 366.02 g/mol

Molar mass of 3 Nitrogen atoms = 3×58.6 = 175.8 g/mol

Moar mass of 2 Phosphorous atoms = 2×31 = 62 g/mol

Moar mass of 8 Oxygen atoms = 8×16 = 128 g/mol

% comosition of Nitrogen = (175.8/366.02)×100% = 48.03%

% comosition of Oxygen = (128/366.02)×100% = 34.97%

% comosition of Phosphorous = (62/366.02)×100% = 16.93%

Hence % composition of nitrogen, oxygen and phosphorous is 48.03%, 34.97% and 16.93% respectively.

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Answer:

mass ( g ) = 348 g

Explanation:

First you know : M = mole / volume (L)

in question you have the M and V and the formula of SUBSTANCE ( KF )

first you get the number of mole from equation above

so 3 = no of mole / 2

no of mole = 3 × 2 = 6 moles

and the moles equation is no of moles = mass ( g ) / molecular weight ( g/mole )

so you have already calculate the moles and you can know the MW from the Question

Mw of KF = 39 + 19 = 58

so n = mass / MW

so 6 = mass / 58

mass ( g ) = 348 g

GOOD LUCK

Answer:

4NO + 6H2O = 4NH3 + 5O2

Explanation:

Think about it this way: there are 4N's 4O's and 12H's and 10O's on both sides that's what makes it balanced

Hope this helps :)

The right answer is Proton.

Additional Information:

There are three types of subatomic particles. They are:

Proton is a positively charged particle,Electron is negatively charged particle and Neutron is charge less.

Hope it will be helpful to you...

Answer:

The correct answer is 6.32 ml

Explanation:

We have the following data:

Mass : m = 9.37 g

Density : d= 1.483 g/mL

The density a substance is equal to the mass of the substance divided into its volume. So, we calculate the volume (V) of chloroform from the mass and density as follows:

[tex]d=\frac{m}{V}[/tex]   ⇒  [tex]V = \frac{m}{d} = \frac{9.37 g}{1.483 g/ml} = 6.32 ml[/tex]

Answer:

Fusion doesn't produce runway chain reactions the way fission can, so there's no need to worry about meltdowns.

Answer: 179 of [tex]H_2O[/tex] will be produced.

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} H_2=\frac{20.0g}{2.01g/mol}=9.95moles[/tex]

[tex]2H_2+O_2(g)\rightarrow 2H_2O[/tex]

According to stoichiometry :

2 moles of [tex]H_2[/tex] give =  2 moles of [tex]H_2O[/tex]

Thus 9.95 moles of [tex]H_2[/tex] will require=[tex]\frac{2}{2}\times 9.95=9.95moles[/tex]  of [tex]H_2O[/tex]

Mass of [tex]H_2O=moles\times {\text {Molar mass}}=9.95moles\times 18g/mol=179g[/tex]

Thus 179 of [tex]H_2O[/tex] will be produced.

Answer:

5) You push hard on a heavy desk and try to move it. You do work on the desk: A.- Whether you move it or not, as long as you exert a force. B.- Only if the desktop moves. C.- Only if the desktop does not move. D.- Never; the desk does work on you. E.- None of the above. CAN YOU HELP ME?

B.- Only if the desktop moves.

Explanation:

No work is done if a force is exerted but no displacement occurs. A force perpendicular to the displacement does no generate work.

Answer:

it should be +0.46 :)

Explanation:

I just took the test and got it right.

Answer:

I think it's +1.14 V, but don't take my word for it..

Answer:

B.) Go down

Explanation:

Hello,

In this case, a strong base like NaOH has a high pH based on the scale wherein 7 is neutral, above 7 is basic and below 7 is acid. In such a way, by adding an acid, having a low pH, once it is added, the pH will go down until the equivalence point, which for strong base and strong acid should be 7.

Best regards.

Answer:

B) Go down

Explanation:

pH is defined as -log [H⁺], that means when concentration of H⁺ increases the pH decreases and when concentration of H⁺ decreases, pH increases.

When a strong acid as HCl is added to a solution, it is dissolved, thus:

HCl → H⁺ + Cl⁻

Thus, addition of a strong acid decreases pH because concentration of H⁺ increases.

Right answer is:

B) Go down

Answer:

b

Explanation:

Answer:

it has  a huge surface-to-volume ratio, very high porosity and completely different physiochemical properties.

Explanation:

idk if the answer is good  !

sorry

Answer:

Aluminium Chloride and Hyrdron, also known as proton/

Explanation:

Answer:

carcinogen

Explanation:

cigarette smoke and UV radiation both of the capability to cause cancer cells in living tissue, meaning they can both be classed as carcinogens

Answer:

1.5 L

Explanation:

Step 1:

The balanced equation for the reaction. This is given below:

HCl + NaOH —> NaCl + H2O

From the balanced equation above, The mole ratio of the acid (nA) = 1

The mole ratio of the base (nB) = 1

Step 2:

Data obtained from the question. This includes the following:

Molarity of acid (Ma) = 0.5M

Volume of acid (Va) =..?

Volume of base (Vb) = 1L

Molarity of base (Mb) = 0.75M

Step 3:

Determination of the volume of the acid needed for the reaction.

Using the formula:

MaVa/MbVb = nA/nB

The volume of the acid needed for the reaction can be obtained as follow:

0.5 x Va / 0.75 x 1 = 1

Cross multiply

0.5 x Va = 0.75 x 1

Divide both side by 0.5

Va = 0.75 /0.5

Va = 1.5 L

Therefore, the volume of the acid, HCl needed for the reaction is 1.5L

Answer:

An antioxidant helps in the mopping up and elimination of free radicals and a common example is Glutathione. Oxidation reactions Involves the transfer of electrons or addition of oxygen to a substance.

Antioxidants help in decreasing or prevention of the oxidation of the molecules due to free radicals being formed which causes damage in the cells of animals.

Answer: A. They show the oxidation and reduction halves of a reaction.

Explanation:

Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reactions occur simultaneously.

For a redox reaction: [tex]A+B^+\rightarrow A^++B[/tex]

Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.

oxidation half at anode : [tex]A\rightarrow A^++e^-[/tex]

Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.

reduction half at cathode:  [tex]B^++e^-\rightarrow B[/tex]

Half-reactions show the oxidation and reduction halves of a reaction. The correct answer is option A.

Oxidation is a chemical reaction that involves the loss of electrons by a molecule, atom, or ion. This process results in an increase in the oxidation state of the species undergoing oxidation.

Half-reactions are used to show the oxidation and reduction half of the reaction separately, which makes it easier to balance the overall reaction and to identify the species that are being oxidized and reduced.

In conclusion, half-reactions are used to show the oxidation and reduction halves of a redox reaction separately. Option A is the correct answer.

Learn more about oxidation here:

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Answer:

option c

Explanation:

ffuunkie. tfnhc dhrhrjebrjeieie

Answer:

in w

Explanation:

first blood enter renal artery which enter glomerous( where blood is filtrated) and then to Bowman carpusle(take the filtrated blood)

and then to proximal tubular(absorbed salt) and then to loop of hanle (y)(absorb water) and then to distal tubule then to ureter (z) and then to renal vein(x)(to go to urinary bladder)

Answer:  A basic solution is defined as a solution which has more hydroxide (OH-) ions than hydronium ions (H+)

Answer:

Dogs naturally lose old or damaged hair by shedding. Although shedding. and yes

Answer:

6Fe^2+(aq) -------> 6Fe^3+(aq) + 6e

Explanation:

The balanced oxidation half equation is;

6Fe^2+(aq) -------> 6Fe^3+(aq) + 6e

A redox reaction is actually an acronym for oxidation-reducation reaction. Since the both reactions are complementary, there can't be oxidation without reduction and there can't be reduction without oxidation.

The main characteristic of redox reactions is that electrons are transferred in the process. The number of electrons transferred is usually deduced from the balanced reaction equation. For this reaction, the balanced overall reaction equation is;

Cr2O7^2–(aq) + 6Fe^2+(aq) +14H^+(aq)→ 2Cr^3+(aq) + 6Fe^3+ (aq) + 7H2O(l)

It is clear from the equation above that six electrons were transferred. Thus six Fe^2+ ions lost one electron each in the oxidation half equation as shown in the balanced oxidation half equation above.

Answer:

D

Explanation:

Answer:

It is a typical fires that started out of a lightning strike, or people carelessly starting it, or accidentally, or even arson, that went un-noticed and got out of hand.

Answer:

Explanation:

Forest fires always start by one of two ways - naturally caused or human caused. Natural fires are generally started by lightning, with a very small percentage started by spontaneous combustion of dry fuel such as sawdust and leaves. On the other hand, human-caused fires can be due to any number of reasons.

Answer:

For 2. the answer is 15.0 mL

For other examples, you can solve by exact way as I have solved the 2nd example.

I have writen down all the balanced chemical reaction equation for examples 1, 3, 4, 5 for you. ( picture 2 )

Explanation:

Please see the step-by-step solution in the picture attached below.(picture 1)

Hope this answer can help you. Have a nice day!

Answer:

[tex]m_{H_2}=0.504gH_2[/tex]

Explanation:

Hello,

In this case, since the reaction is:

[tex]2 Na + 2 H_2O \rightarrow 2 NaOH + H_2[/tex]

We notice that since there is an excess of water, we can directly compute the yielded grams of hydrogen by using the following stoichiometric procedure, considering the 2:1 molar ratio between sodium and hydrogen (notice the 2 before the sodium and the 1 before the hydrogen at the chemical reaction) and that gaseous hydrogen has a molar mass of 2 g/mol:

[tex]m_{H_2}=11.50gNa*\frac{1molNa}{22.98gNa} *\frac{1molH_2}{2.02molNa} *\frac{2gH_2}{1molH_2} \\\\m_{H_2}=0.504gH_2[/tex]

Best regards.

Answer:

0.503g of H₂ are produced

Explanation:

Based on the chemical reaction:

2 Na + 2 H₂O → 2 NaOH + H₂

2 moles of Na react with 2 moles of water to produce 2 moles of NaOH and 1 mole of H₂

11.50g of Na -limiting reactant, molar mass 22.99g/mol- are:

11.50g× (1mol / 22.99g) = 0.500 moles of Na.

As 2 moles of Na produce 1 mole of H₂:

0.500 moles of Na × (1 mole H₂ / 2 moles Na) = 0.250 moles of H₂

As molar mass of H₂ is 2.01g/mol:

0.250 moles of H₂ × (2.01g / 1mol) = 0.503g of H₂ are produced

Answer:

[tex]\large \boxed{\text{D.) 91 kPa}}[/tex]

Explanation:

We can use the Ideal Gas Law — pV = nRT

Data:

V = 15.0 L

n = 0.55 mol

T = 300 K

Calculation:

[tex]\begin{array}{rcl}pV & =& nRT\\p \times \text{15.0 L} & = & \text{0.55 mol} \times \text{8.31 kPa$\cdot$ L$\cdot$K$^{-1}$mol$^{-1}\times$ 300 K}\\15.0p & = & \text{1370 kPa}\\p & = & \textbf{91 kPa}\end{array}\\\text{The pressure in the container is $\large \boxed{\textbf{91 kPa}}$}[/tex]