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3 years ago

An element is made up from ?

Chemistry

2 answers:

mafiozo [28]3 years ago

5 0

Answer:

An element is made up from Atoms

sertanlavr [38]3 years ago

4 0

Answer:

Atoms

Explanation:

Elements are the chemical combinations of two or more atoms of the same kind

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Looters break a statue into pieces. How do you expect the weathering of pieces of rock to change?

andreyandreev [35.5K]

The statue will weather faster because of more surface area.

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3 years ago

It takes 281.7 kJ of energy to remove 1 mole of electrons from the atoms on the surface of lithium metal. If lithium metal is ir

Alex17521 [72]

Answer:

The maximum kinetic energy of electron is = 2.93 × $10^{-19}$ Joule

Explanation:

We know that total energy

$E = \frac{hc}{\lambda}$ ------------ (1)

Here h = plank's constant = 6.62 × $10^{-34}$ J s

c = speed of light = 3 × $10^{8}$ $\frac{m}{s}$

$\lambda$ = 261 nm = 261 × $10^{-9}$ m

Put all these values in equation (1) we get

E = 7.6 × $10^{-19}$ J

We know that

Total energy = Energy to remove an electron + K.E of electron

Energy to remove an electron = $\frac{281.7 (1000)}{(6.023)10^{23} }$

Energy to remove an electron = 4.67 × $10^{-19}$ J

K.E of electron = Total energy - Energy to remove an electron

K.E of electron = 7.6 × $10^{-19}$ - 4.67 × $10^{-19}$

K.E of electron = 2.93 × $10^{-19}$ Joule

Therefore the maximum kinetic energy of electron is = 2.93 × $10^{-19}$ Joule

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3 years ago

Based upon the following equation: P4 + 5 O2 --> 2 P2O5 How many grams of P4 (molar mass 124 g = 1 mole) are necessary to rea

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Sorry I don't know this

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3 years ago

A cord is used to vertically lower an initially stationary block of mass m kg at a constant downward acceleration of g/4. the bl

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(a) We know that work is the product of Force and Distance so: (in this case Distance is negative since going down so –d)

work = force * distance

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work = Mgd 

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KE = net work

KE = Mgd/4 

(d) The velocity is:

v = √(2*KE/M)

Plugging in the value of KE from c:

v = √(2*Mgd / 4M)

v = √(gd / 2)

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3 years ago

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Answer:

Explanation:

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