Which mixture can be separated through filtration because one the substances is insoluble in water?

Identify the neutral element represented by this excited-state electron configuration, then write the ground-state electron conf

sineoko [7]

Answer:

1s² 2s² 2p³

Nitrogen

Explanation:

Excited state configuration: 1s² 2s² 2p² 3s¹

Unknown:

Ground state configuration = ?

Element symbol = ?

Solution:

Let us start by understanding what a ground state configuration entails:

A ground state configuration shows the lowest allowed energy levels of an atom. The excited state denotes when electrons have moved to higher energy levels away from their ground state.

The superscript in the configuration depicts the number of electrons in each of the sublevels.

We can use this number to identify the atom we are dealing with:

Total number of electrons = 2 + 2 + 2 + 1 = 7 electrons

The element with 7 electrons on the periodic table is Nitrogen.

Now, the ground state configuration:

In writing the electronic configuration of an atom, certain rules must be complied with.

Aufbau's principle states that the sublevels with lower energies are filled up before those with higher energies. The order of filling is:

1s 2s 2p 3s 3p 4s etc

To fill the s-orbital = 2 electrons

p-orbital = 6 electrons

The outermost shell electrons are usually the ones excited.

Now, the 3s¹ shell is an excited one taking 1 electron from the second energy level;

The ground state configuration is 1s² 2s² 2p³

5 0

3 years ago

Strontium-90 is a radioisotope that will decrease in mass by one-half every 29 years. How many years will it take for a 10.0-gra

Lelechka [254]

Answer: It will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams

Explanation:

Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

Half life is represented by $t_{\frac{1}{2}$

$t_{\frac{1}{2}=\frac{0.693}{\lambda}$

$\lambda$ = rate constant

Given : Strontium-90 decreases in mass by one-half every 29 years , that is half life of Strontium-90 is 29 years.

As half life is independent of initial concentration, it will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams as the amount gets half.

7 0

3 years ago

Some growth regulators are useful to farmers and gardeners.<br> O True<br> O False

lisov135 [29]

Answer:

True

Explanation:

The first artificial use of a PGR was to stimulate the production of flowers on pineapple plants. They are now used widely in agriculture. Plant hormones are also used in turf management to reduce the need to mow, to suppress seedheads, and to suppress other types of grass.

3 0

3 years ago

This question in the screenshot

Morgarella [4.7K]

Mass of hydrate + crucible = 47.29 g

Mass of anhydrous salt = 2.7 g

Molar mass of anhydrous salt CuSO4 = 159.5 g

Given,

mass of empty crucible = 42.45 g

mass of hydrate salt= 4.84 g

mass of crucible after first heating = 46.1 g

mass of crucible after second heating= 45.153 g

mass of crucible after third heating= 45.15 g

so, as per the question we need to find...

Mass of hydrate + crucible = ? g

Mass of anhydrous salt = ? g

Molar mass of anhydrous salt CuSO4 = ? g

∴Mass of hydrate + crucible = 42.45 + 4.48 = 47.29 g

The given salt is in hydrate form, to remove water from this molecule we need to perform heating .

So we are taking the substance into the crucible as it is in less quantity.

Here, we performed heating 3 times and note the weight after every heating.

After this, assume that the water is totally evaporated and the remaining salt is in anhydrous form,

∴ Mass of anhydrous salt = 45.15 - 42.45 = 2.7 g

To find the molar mass of anhydrous salt of CuSO4,

atomic weight of Cu = 63.5 g

atomic weight of S = 32 g

atomic weight of O =16 g

∴ molar mass of anhydrous salt of CuSO4 = 63.5 + 32 + (16 ×3)

=159.5 gm

Learn more about molar mass here...

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5 0

2 years ago

2CO + 2NO yields 2CO2 + N2 which element was oxidized

aalyn [17]

2C⁺²O⁻² + 2N⁺²O⁻² = 2C⁺⁴O⁻²₂ + N₂⁰

C⁺² → C⁺⁴ + 2e⁻

carbon was oxidized

5 0

3 years ago