All categories

3 years ago

What is Mendeleev most known for?

Chemistry

1 answer:

fenix001 [56]3 years ago

4 0

Dmitri Mendeleev devised the first periodic table.

You might be interested in

How many moles of sodium ions are present in 0.25 kg of a 2.0 m solution of sodium chloride in water

LenKa [72]

0.50 is the answer on edge

8 0

4 years ago

What is the empirical formula

Radda [10]

Answer:

a formula giving the proportions of the elements present in a compound but not the actual numbers or arrangement of atoms.

Explanation:

4 0

2 years ago

It takes 495.0 kJ of energy to remove 1 mole of electron from an atom on the surface of sodium metal. How much energy does it ta

Zigmanuir [339]

Answer:

$\lambda=241.9\ nm$

Explanation:

The work function of the sodium= 495.0 kJ/mol

It means that

1 mole of electrons can be removed by applying of 495.0 kJ of energy.

Also,

1 mole = $6.023\times 10^{23}\ electrons$

So,

$6.023\times 10^{23}$ electrons can be removed by applying of 495.0 kJ of energy.

1 electron can be removed by applying of $\frac {495.0}{6.023\times 10^{23}}\ kJ$ of energy.

Energy required = $82.18\times 10^{-23}\ kJ$

Also,

1 kJ = 1000 J

So,

Energy required = $82.18\times 10^{-20}\ J$

Also, $E=\frac {h\times c}{\lambda}$

Where,

h is Plank's constant having value $6.626\times 10^{-34}\ Js$

c is the speed of light having value $3\times 10^8\ m/s$

So,

$79.78\times 10^{-20}=\frac {6.626\times 10^{-34}\times 3\times 10^8}{\lambda}$

$\lambda=\frac{6.626\times 10^{-34}\times 3\times 10^8}{82.18\times 10^{-20}}$

$\lambda=\frac{10^{-26}\times \:19.878}{10^{-20}\times \:82.18}$

$\lambda=\frac{19.878}{10^6\times \:82.18}$

$\lambda=2.4188\times 10^{-7}\ m$

Also,

1 m = 10⁻⁹ nm

So,

$\lambda=241.9\ nm$

6 0

3 years ago

The moon cannot be seen during which phase?

ycow [4]

New moon is the phase in which it cannot be seen

8 0

4 years ago

Read 2 more answers

7. Ionic bonds are at one end of the bond spectrum. What kinds of bonds are at the other end?

blondinia [14]

Answer:

non-polar covalent bonds

this is when the electronegativity difference between the two non-metal atoms is very little to cause a partial charge (delta positive and delta negative; δ+ and δ-) on the atoms

4 0

2 years ago