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3 years ago

5

Using your periodic table, what is the number of protons in an atom of sodium

1 answer:

Romashka-Z-Leto [24]3 years ago

3 0

Answer:

It would be 11

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PLZZZZZZZ HELPPPP MEEEE ASAP CHEMISTRY QUESTION DOWN BELOW How can you identify a reversible reaction from a chemical equation?

zalisa [80]

it's the third one The chemical equation will have two arrows pointing in different directions. !

7 0

3 years ago

Read 2 more answers

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

3 0

3 years ago

Calculate the percent of each component in the mixture. Show your calculations. Circle final answers.

Colt1911 [192]

Answer:

See Explanation

Explanation:

The question is incomplete; as the mixtures are not given.

However, I'll give a general explanation on how to go about it and I'll also give an example.

The percentage of a component in a mixture is calculated as:

$\%C_E = \frac{E}{T} * 100\%$

Where

E = Amount of element/component

T = Amount of all elements/components

Take for instance:

In $(Ca(OH)_2)$

The amount of all elements is: (i.e formula mass of $(Ca(OH)_2)$ )

$T = 1 * Ca + 2 * H + 2 * O$

$T = 1 * 40 + 2 * 1 + 2 * 16$

$T = 74$

The amount of calcium is: (i.e formula mass of calcium)

$E = 1 * Ca$

$E = 1 * 40$

$E = 40$

So, the percentage component of calcium is:

$\%C_E = \frac{E}{T} * 100\%$

$\%C_E = \frac{40}{74} * 100\%$

$\%C_E = \frac{4000}{74}\%$

$\%C_E = 54.05\%$

The amount of hydrogen is:

$E = 2 * H$

$E = 2 * 1$

$E = 2$

So, the percentage component of hydrogen is:

$\%C_E = \frac{E}{T} * 100\%$

$\%C_E = \frac{2}{74} * 100\%$

$\%C_E = \frac{200}{74}\%$

$\%C_E = 2.70\%$

Similarly, for oxygen:

The amount of oxygen is:

$E = 2 * O$

$E = 2 * 16$

$E = 32$

So, the percentage component of oxygen is:

$\%C_E = \frac{E}{T} * 100\%$

$\%C_E = \frac{32}{74} * 100\%$

$\%C_E = \frac{3200}{74}\%$

$\%C_E = 43.24\%$

5 0

3 years ago

Who uses chemicals ?

nordsb [41]

Is there answer choices ??

4 0

3 years ago

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Not enough air is pumped into an inflatable life raft to make completely filled out the atm pressure is 14.7psi what is the pres

sasho [114]

If you do not inflate the life raft to make completely filled out, as long as you do not press or squeeze the life raft, the air inside it will be in equilibrium with the air outside the raft, and so the pressure inside the life raft will be the same atmospheric pressure, 14.7 psi.

Note that when the raft is swollen, if you punch it, the air will leave from it which means that the pressure inside is greater than the atmospheric pressure.

5 0

3 years ago