How many significant figures does 0.005505 have

Which of the following example(s) from everyday life are made possible by modern chemistry?

lorasvet [3.4K]

Answer:

I believe it is c

Explanation:

........................

7 0

3 years ago

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How fast must a 56.5-g tennis ball travel in order to have a de Broglie wavelength that is equal to that of a photon of green li

nikklg [1K]

Answer:vv

$v=2.17\times 10^{-26}\ m/s$

Explanation:

The expression for the deBroglie wavelength is:

$\lambda=\frac {h}{m\times v}$

Where,

$\lambda$ is the deBroglie wavelength

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

m is the mass of = $56.5\ g=0.0565\ kg$

v is the speed.

Wavelength = 5400 Å = $5400\times 10^{-10}\ m$

Applying in the equation as:-

$5400\times 10^{-10}=\frac{6.626\times 10^{-34}}{0.0565\times v}$

$v=\frac{331300000}{10^{34}\times \:1.5255}\ m/s$

$v=2.17\times 10^{-26}\ m/s$

7 0

3 years ago

A 5 grams sample of liquid water evaporates into gaseous water in a closed container, expanding in the process. What is the mass

padilas [110]

We have get the mass of gaseous water after evaporation in a closed container.

The mass of water vapor after evaporation is 5 grams.

In closed container, there is no exchange in mass from system to surrounding, only heat may exchange. The number of moles of water vapour remains unchanged as 5 gram water is heated in closed container.

Due to heating, liquid water gets evaporated and intermolecular distance between water molecules increases in gaseous state than liquid state and intermolecuar force of attraction decreases.

Randomness of molecules increases in gaseous state than liquid state.

5 0

3 years ago

In which reaction does the oxidation number of hydrogen change? In which reaction does the oxidation number of hydrogen change?

dedylja [7]

Answer: The correct answer is $2Na(s)+2H_2O(l)\rightarrow 2NaOH(aq.)+H_2(g)$

Explanation:

Oxidation number is defined as the number which is given to an atom when it looses or gains electron. When an atom looses electron, it attains a positive oxidation state. When an atom gains electron, it attains a negative oxidation state.

Oxidation state of the atoms in their elemental state is considered as 0. Hydrogen is present as gaseous state.

For the given chemical reactions: