PLEASE HELP!! :((((((((((((((((((((((((

Answer:

The answer is

Explanation:

To find the number of entities of a substance given it's number of moles we use the formula

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question

n = 2.0 moles

We have

N = 2 × 6.02 × 10²³

We have the final answer as

Hope this helps you

Number of moles of boron (B) = 2

We have to find number of atoms present in the given amount of boron[tex].[/tex]

➤ We know that 1 mole of substance contains 6.022×10²³ particles (atoms/molecules).

★ Number of atoms present in B :

⭆ N = n × [tex]\sf{N_A}[/tex]

⭆ N = 2 × 6.022 × 10²³

⭆ N = 12.044 × 10²³

⭆ N = 1.2 × 10²⁴

Answer:

bonding electron

Explanation:

because they will bond together.

Energy required : 4.23 x 10⁹ J

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 V=L\times W\times H\\\\V=10\times 4\times 3=120~m^3[/tex]

ρ = 1000 kg/m³

[tex]\tt mass=\rho\times V\\\\mass=1000~kg/m^3\times 120~m^3=120,000~kg[/tex]

c water = 4200 J/ kg ° C  

[tex]\tt Q=m.c.\Delta T\\\\Q=1.2\times 10^5\times 4200\times (28.6-20.2)\\\\Q=42336\times 10^5=4.23\times 10^9~J[/tex]

Answer:

 ²²⁶₈₈Ra → ²²²₈₆Rn + ⁴₂He  +⁰₀γ

Explanation:

This radioactive decay occurs when the unstable radium-226 atom wants to lose energy by emitting an alpha particle from its nucleus which is an helium nucleus with no electron. The radium (86) is transformed to radon(Rn) where the atomic number of radium (88) is reduced by two units into radon, Rn (86) and mass number reduced by 4 units.

The equation for the transformation is;

 ²²⁶₈₈Ra → ²²²₈₆Rn + ⁴₂He  +⁰₀γ  where

²²⁶₈₈Ra ---------radium-226

²²²₈₆Rn -------radon-222

⁴₂He ----------alpha particle

⁰₀γ ------------energy

Note that ⁴₂He can also be written as : ⁴₂∝

Answer:

it is alpha decay

Explanation:

im albert einstien

Answer:

B: Leather Jacket

Explanation: I hope that this helped :)

Answer:

The individual substances in a mixture can be separated using different methods, depending on the type of mixture. These methods include filtration, evaporation, distillation and chromatography.

Explanation:

Answer:

Answers in explanation.

Explanation:

30. A (A chemical changes changes the chemical properties)

31. C (rusting is an example of a chemical change

32. B (A reaction requires energy, so some energy will be expelled)

33. B (Color change is an example of a chemical change)

34. A (The law of the conservation of mass: Mass and Energy cannot be created nor destroyed)

Answer:

kingdom, phylum, class, order, family, genus and species.

Explanation:

Answer:

A joule divided a second

Explanation:

i took the test

plz give me brainlist :)

Answer:

D

Explanation:

hi! a chemical change changes the composition of the material. in A, even though the glass is broken, it is still glass. for B, even though the wood is chopped, it is still wood. for C, even though the can is crushed, it is still a can. D is a chemical change because the milk's taste changes, meaning its chemical composition changed and a reaction occurred. it is no longer the original milk.

The event represents a chemical change is milk turning sour. Hence option D is correct.

Chemical change is defined as a transformation of one material into another, the formation of new materials with distinct properties, and the creation of one or more new substances. Chemical synthesis, or, alternatively, chemical breakdown into two or more separate molecules, occurs when one material reacts with another to create a new substance.

In the case of milk, it contains a sugar called lactose as well as lactobacillus, a type of bacteria that is completely safe and uses the lactose to produce energy and lactic acid. This is what gives milk its sour flavor. When the taste of the milk changes, a chemical reaction has taken place, changing its chemical makeup. It isn't the original milk anymore.

Thus, the event represents a chemical change is milk turning sour. Hence option D is correct.  

To learn more about chemical change, refer to the link below:

https://brainly.com/question/23693316

#SPJ2

Answer: true

Explanation:

Answer:

By gaining elections

Explanation:

Cations are formed when neutral atoms loss electrons and when they gain back the lost electrons the charges are neutralized.

Eg. Cu=Cu2+ + 2é

Cu2+ + 2é=Cu

Answer:

A. Ba

C. Cu

D. H

Explanation:

HOPE THIS HELPS

Answer:

Explanation:

It describes how much heat must be added to a unit of mass of a given substance to raise its temperature by one degree Celsius. ... The mass m, specific heat c, change in temperature ΔT, and heat added (or subtracted) Q are related by the equation: Q=mcΔT.

Answer:

The formula q=mcΔt explained below

Explanation:

so q represents the amount of heat energy. M is the mass of the object and c is the temperature of the object. Δt also known as delta is the change in temperature. It would be the final temperature minus the original temperature.

Nonane (b) has the highest melting point.

-----------------------------

A caveat: I'm assuming that we're dealing with the straight-chain isomers of these alkanes (specifically pentane and nonane). The straight-chain isomer of pentane (n-pentane, CH3-[CH2]3-CH3) has a melting point of -129.8 °C; the straight-chain isomer of nonane (n-nonane, CH3-[CH2]7-CH3) has a melting point of -53.5 °C. The pattern holds as you go down (or up): The more carbon atoms, the higher the melting point. So, in decreasing order of melting points here, you'd have the following: nonane > pentane > butane > ethane.

However, one structural isomer of pentane, neopentane, has a melting point of -16.4 °C, which is higher that the melting point of n-nonane despite neopentane having the same molecular formula as its straight-chain isomer. Of course, you're not to blame for coming up with this question; this is just some extra info to keep in mind.

Answer:

A

Explanation:

Answer:

B. Divergent

The rift formed in the Divegent tectonic boundary between the North America and Eurasian Plates and is located now in Iceland (Im sorry im not good at explaining)

Explanation:

Electronic configuration of Nitrogen -

₇N = 1s² 2s² 2p³

Answer:

B

Explanation: Lithium, sodium, and potassium, etc. all react with water

Answer: The hydrosphere includes all of the water which is on the surface of the planet. A planet's hydrosphere can be vapor, ice, or liquid.

Answer:

hydrosphere

Explanation:

Answer A:

The organism which provides energy directly and/or indirectly to all of the other organisms is the garden plants.

Explanation:

Plants are generally found at the lowest part of the pyramid/food chain. They are also called Autorotrophs because they are the primary producers of energy from which the entire pyramid feeds off.

The other animals/organisms on the pyramid are called Heterotrophs because they depend directly or indirectly on the primary energy producers.

Answer B:

The Slug and the Aphid feed are herbivorous. So they are in competition for the garden plants. If one of them, for some reason, decreased in population, the other will have more food to eat.

Cheers

Not sure what you exactly mean, but I think what you are talking about are the spheres of earth (Lithosphere, Hydrosphere, Atmosphere, and Biosphere.)

Lithosphere (Terrestrial) is the land on earth. Hydrosphere (Hydrologic) is the water on earth.

I'm not sure if this is 100% correct but I'm guessing this is what you are referring to. It could be different across different science classes.

Answer:

I believe it is 2?

Explanation:

;v;

Answer:

6

Explanation:

the sig figs are 850320

Answer:

Fractional distillation is essentially the same as simple distillationexcept that a fractionating column is placed between the boiling flask and the condenser. The fractionating column is usually filled with glass or plastic beads. These beads improve the separation between the liquids being distilled.

Explanation:

Answer:

Explanation:

The difference between simple and fractional distillation is the number of times that the liquid is vaporized and condensed. Simple distillation condenses the liquid once, so the boiling points of the two liquids must be far apart to make it efficient. The number of simple distillations in a fractional distillation apparatus depend on the length and efficiency of the fractionating column. The process is the same; the difference is mainly one of iteration.

brainliest pweaseeee

Answer:

The final step of the scientific method is to communicate the results​

Answer:

The specific heat of water is greater than that of the metal

Explanation:

When water is put into a hot metal pan of equal mass, we discover that the pan cools down more than the water heats up because heat is rapidly transferred from the pan to the water.

This happens because the specific heat capacity of water is much greater than that of the pan hence heat is more quickly transferred from the pan to the water.