what's radioactivity with a clear definition​

Answer:

B. Potential energy

Explanation:

It's not mechanical energy, because it is not doing work

It's not kinetic energy because it;s not moving

It's not gravitational energy because it is not above the ground

It is potential energy because it is stored energy

Answer:

There are 0.5 mole in 20g of argon.

Explanation:

40 g of argon = 1mole

Then 20g of argon is,

→ 1/40 × 20

→ 0.5 mole

Answer:

[tex]n = \frac{mass}{molar \: mass} \\ n = \frac{20g}{39.948 \frac{g}{mol} } \\ n = 0.5 \: mol \: of \: argon[/tex]

Explanation:

hope this makes sense

:)

Answer:

-3169

Explanation:

trust the process

-3169 kJ/mol is the enthalpy of combustion when 1 mol [tex]C_6H_6(g)[/tex] completely reacts with oxygen.

Explanation:

Given:

The reaction of combustion of [tex]C_6H_6(g)[/tex] along with enthalpies of formation of the compounds.

To find:

The enthalpy of combustion when 1 mol [tex]C_6H_6(g)[/tex]  completely reacts with oxygen.

Solution:

[tex]2C_6H_6(g) + 15O_2(g) \rightarrow 12CO_2(g) + 6H_2O(g)[/tex]

Enthalpy of the reaction:

[tex]\Delta H^o_{rxn}=\sum [\Delta H^o_{f,products}]-\sum [\Delta H^o_{f,reactants}]\\=[12mol\times \Delta H^o_{f.CO_2(g)}+6mol\times \Delta H^o_{f,H_2O(g)}]-[2 mol\times \Delta H^o_{f.C_6H_6(g)}+15\times \Delta H^o_{f,O_2(g)}]\\=[12mol\times (-393.50 kJ/mol)+6mol\times (-241.82 kJ/mol)]-[2mol\times 82.90kJ/mol+15mol\times 0 kJ/mol]\\=-6338.72 kJ[/tex]

[tex]2C_6H_6(g) + 15O_2(g) \rightarrow 12CO_2(g) + 6H_2O(g).\Delta H^o_{rxn}=-6338.72 kJ[/tex]

When 1 mole of [tex]C_6H_6(g)[/tex]  reacts with oxygen gas:

[tex]=\frac{\Delta H^o_{rxn}}{\text{2 mol of } C_6H_6}\\=\frac{-6338.72 kJ}{2 mol}\\=-3169.36 kJ/mol\approx -3169 kJ/mol[/tex]

-3169 kJ/mol is the enthalpy of combustion when 1 mol [tex]C_6H_6(g)[/tex] completely reacts with oxygen.

Learn more about enthalpy of combustion here:

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endothermic

requires energy to occure

H₂ + ½O₂ → H₂O

2g → 18g

So, 18g water needs 2g H₂

So, 1g water needs 2/18g H₂

So, 180g water needs 2/18 x 180g H₂

→ 20 litres of H₂

Answer:

Explanation:

Molar mass of water, H2O = 2 + 16 = 18

So 180g of water contains 10M

H2 + O -> H2O

10M of Hydrogen is needed to produce 10M of water.

Molar volume at STP = 22.4L

So 10M of Hydrogen at STP = 224L

With Ideal Gas Law, P1V1/T1 = P2V2/T2

At STP, P1 = 1atm, T1=273K

At 0.97atm and 24c (273+24 = 297K), 10M of Hydrogen will take up:

1*224/273 = 0.97*V2/297

V2 = 224*297/273/0.97

= 251.23L

So the answer is 251.23L

Answer: The mass of water produced is 27 g

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of pentane = 18 g

Molar mass of pentane = 72.15 g/mol

Plugging values in equation 1:

[tex]\text{Moles of pentane}=\frac{18g}{72.15g/mol}=0.250 mol[/tex]

The given chemical equation follows:

[tex]C_5H_{12}+8O_2\rightarrow 5CO_2+6H_2O[/tex]

By the stoichiometry of the reaction:

If 1 mole of pentane produces 6 moles of water

So, 0.250 moles of pentane will produce = [tex]\frac{6}{1}\times 0.250=1.5mol[/tex] of water

Molar mass of water = 18 g/mol

Plugging values in equation 1:

[tex]\text{Mass of water}=(1.5mol\times 18g/mol)=27g[/tex]

Hence, the mass of water produced is 27 g

Answer:

A. Sodium (Na)

Explanation:

The total number of electrons in the outermost principal energy level of an element is called the valence electrons of that element.

Na (11)---→1s2 2s2 2p6 3s1

There 1 electron in the outermost principal energy level of Sodium. So, the number of valence electron of Sodium is 11.

Answer:

Na

Explanation:

I was learning about it recently, that dude's right, it's Sodium

Answer: There are [tex]2.032 \times 10^{25}[/tex] molecules [tex]S_{2}[/tex] gas are in 756.2 L.

Explanation:

It is known that 1 mole of any gas equals 22.4 L at STP. Hence, number of  moles present in 756.2 L are calculated as follows.

[tex]Mole = \frac{Volume}{22.4 L}\\= \frac{756.2 L}{22.4 L}\\= 33.76 mol[/tex]

According to mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] molecules.

Therefore, molecules of S present in 33.76 moles are calculated as follows.

[tex]1 mol = 6.022 \times 10^{23}\\33.76 mol = 33.76 \times 6.022 \times 10^{23}\\= 2.032 \times 10^{25}[/tex]

Thus, we can conclude that there are [tex]2.032 \times 10^{25}[/tex] molecules [tex]S_{2}[/tex] gas are in 756.2 L.

Answer: 55.7 moles of [tex]H_2O[/tex] are needed to produce the given amount of [tex]H_2[/tex]

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given values:

Moles of [tex]H_2[/tex] = 55.7 moles

The chemical equation for the decomposition of water follows:

[tex]2H_2O\rightarrow 2H_2+O_2[/tex]

By the stoichiometry of the reaction:

If 2 moles of hydrogen gas is produced from 2 moles of water

So, 55.7 moles of hydrogen gas will be produced by = [tex]\frac{2}{2}\times 55.7=55.7mol[/tex] of water

Hence, 55.7 moles of [tex]H_2O[/tex] are needed to produce the given amount of [tex]H_2[/tex]

Taking into account the reaction stoichiometry,

In first place, the balanced reaction is:

2 H₂O → 2 H₂ + O₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The following rule of three can be applied: if by reaction stoichiometry 2 moles of H₂ are produced from 2 moles of H₂O, 55.7 moles of H₂ are produced from how many moles of H₂O?

[tex]moles of H_{2} O=\frac{55.7 moles of H_{2}x 2 moles of H_{2} O}{2 moles of H_{2}}[/tex]

moles of H₂O= 55.7 moles

Finally, 55.7 moles of H₂O is requiredto produce 55.7 moles of H₂.

Learn more about the reaction stoichiometry:

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Answer:

wla dyan ang sagut ehh baka mali yan

Answer:

The products from the neutralization reaction are barium nitrate and water.  

The balanced chemical equation is

2 [tex]HNO_{3}[/tex] +  1 [tex]Ba(OH)_{2}[/tex]  -->  1 [tex]Ba(NO_3)_{2}[/tex] +  2 [tex]H_{2}O[/tex].  

Answer:

Copper oxide + magnesium = copper + magnesium oxide

Explanation:

When copper oxide is heated with magnesium powder, then magnesium oxide and copper are formed.. For example, magnesium is more reactive than copper. ... brown copper coats the surface of the magnesium.

Answer:

2Al(NO3)3+3K2CO3->Al2(CO3)3+6KNO3

So the right answer is 2,3,1,6

Explanation:

First you look at the equation that isn't balance, you can see Al(NO3)3 while Al2(CO3)3, so you put 2 in Al(NO3)3.

Now we have 2Al is correct, but 6NO3. So we have 6KNO3, it also means we have 6K

Finally, we only have 2K as K2CO3 so we put 3 in it, so we have 3K2CO3.

Sorry about my explanation, it's hard to understand but the answer is correct.

Answer:

Hi , your answer is that At impact, the cue ball stops, but transfers all of its momentum and kinetic energy to the other ball, resulting in the hit ball rolling with the initial speed of the cue ball. In an inelastic collision, momentum is conserved, but the total kinetic energy of the system is not conserved

Explanation:

i really hope i helped , pleae give me brainliest , have a nice day and thank you in advance :) .

Answer:

In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.

Answer:

sry, dk

Explanation:

Answer:

Explanation:

Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital. This results in a larger atomic radius.

Answer:

Plants ➯ Mouse ➯ Snake ➯ Hawk ➯ Sun

Explanation:

In Order As A Food Chain

The elements are arranged into food chain like plants ⇒Mouse ⇒ Snake⇒ Hawk ⇒ Sun.

A substance that could not be further decomposed according to any chemical reaction is known as a chemical element.

The flow of nutrients as well as energy through such an ecosystem is described by a food chain. Energy is first produced by plants at the most fundamental level, and then it is used by higher-level species like herbivores. Energy is then transmitted from one carnivore to the next when they eat the herbivores.

The elements are arranged into food chain like plants ⇒Mouse ⇒ Snake⇒ Hawk ⇒ Sun.

To know more about food chain and element

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#SPJ2

Explanation:

Weight loss and weight maintenance.

Muscle gain.

Improved mood.

Improved heart health.

Answer:

Yes

Explanation:

Yes, but almost insignificantly. The regular boiling point of water is 100 degrees celcius, adding a small handfull of salt will increase the boiling point to roughly 100.04 degrees celcius. Therefore, it is almost insignificant but still does affect it. This is mainly because salt changes the way the molecules react thus making it harder for them to change state from liquid to gas. This ultimately causes the water to get hotter before boiling actually occurs.

Answer:

The air that is inside a ship is much less dense than water. That's what keeps it floating

Answer:

6.5 moles of Oxygen are required

Explanation:

Based on the reaction:

CH3OH + 1/2 O2 → CH2O + H2O

1 mole of methanol reacts with 1/2 moles O2 to produce 1 mole of formaldehyde and 1 mole of water.

Thus, to produe 13 moles of formaldehyde, CH2O, are needed:

13 moles CH2O * (1/2mol O2 / 1mol CH2O) =

Answer:

the products are the substances made after the chemical reaction has happened

Explanation:

Answer:

Adding hydrogens, decreasing the number of double bonds in the molecules.

Explanation:

Hydrogen is a catalyst, which means that it accelerates or speeds up the velocity of a chemical reaction, by adding hydrogens to oil it will decrease the number of double bonds in the molecules which will make it solidify over time.

Oil + hydrogen creates substances that are solid at room temperature.

Answer:

The spacing between the terrestrial planets is less than that between the gas planets.

Explanation:

Since the terrestrial planets which are Mercury, Venus, Earth and Mars have a distance of 0.4 AU, 0.7 A.U, 1.0 AU and 1.5 A.U respectively from while the gas planets which are Jupiter, Saturn, Uranus and Neptune have a distance of 5.2 AU, 9.6 AU, 19.6 AU and 30 AU respectively from the sun, we can see that the spacing between the terrestrial planets is much smaller than the spacing between the gas planets.

For example, the spacing between Mercury and Venus is 0.7 AU - 0.4 AU = 0.3 AU while that between Earth and Venus is 1.0 AU - 0.7 AU = 0.3 AU.

Also, the spacing between Earth and Mars is 1.5 AU - 1.0 AU = 0.5 AU.

Also too, the spacing between the gas planets is shown below  the spacing between Jupiter and Saturn is 9.6 AU - 5.2 AU = 4.4 AU while that between Uranus and Saturn is 19.6 AU - 9.6 AU = 10.0 AU.

Also, the spacing between Neptune and Uranus is 30 AU - 19.6 AU = 10.4 AU.

Thus, we can see that the spacing between the terrestrial planets is less than that between the gas planets.

Note that AU means astronomical unit and 1 AU is the distance between the Earth and the Sun. 1 AU = 1.50 × 10⁸ km

Explanation:

u can put them in order crossed are spectator ions. hope this helps:)