All categories

3 years ago

Write an equation that shows the formation of a selenide ion from a neutral selenium atom

Chemistry

1 answer:

Georgia [21]3 years ago

8 0

Answer:

Se + 2e- => Se-2

Explanation:

Ions are electrically charged particles, formed due to the gain or loss of electrons by an atom.

There are two types of ions cations and anions. An element that loses their electrons and forms positive ions are cations while metals and element that gains one or more electrons and forms negative ions are anions.

Selenium is an atom with atomic number 34 and represented as Se. The electronic configuration of Se is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p4. Selenium will gain 2 more electrons to complete it p orbital and form an ion Se-2.

The equation is as below:

Se + 2e- => Se-2

You might be interested in

Draw a complete structural formula and a condensed structural formula for(a) three compounds of formula C3H8O (b) five compounds

Marat540 [252]

Answer:

Explanation:

A. Attached is a page which contain the structural formula of the three compounds of C3H80.

Condensed structural formula of C3H8O:

Propan-1-ol: CH3CH2CH2OH

Propan-2-ol: CH3CH(OH)CH3

Methoxy methane: CH3OCH2CH3

B. Attached are is a page which contain the structural formula of the three compounds of C3H60.

Condensed structural formula of C3H6O:

Propanal: CH3CH2CHO

Propanone: CH3COCH3

Cyclopropanol: (C3H5)OH

2-propen-1-ol: CH2CHCH2OH

1-propenol: CH3CHCHOH

4 0

4 years ago

What is the radius of a hydrogen atom whose electron is bound by 0.544 ev? express your answer with the appropriate units?

insens350 [35]

First, we need to calculate the principal quantum number n for this electron, using the equation:
E = (-13.60 eV) / (n x n)
where E is the energy that is used to bound the electron (here, E = - 0.544 eV).
- 0.544 eV = (-13.60 eV) / (n x n)
n x n = (- 13.60 eV) / (- 0.544 eV)
n x n = 25
n = 5

The orbital radius that is equal to the radius of a hydrogen atom is calculated using the equation:
r = 0.053 nm x n x n
r = 0.053 nm x 5 x 5
r = 0.053 nm x 25
r = 1.325 nm

6 0

3 years ago

(0904) How many atoms are there in 56.2 grams of Krypton, Kr?

Luba_88 [7]

Answer:

56.2÷6.02×10^23

=9.34×10^23

Explanation:

Divide the given mass of the atom by the mass of an Atom (the avogadro's constant) to find the number of atoms in the given mass.

8 0

3 years ago

Calculate the number of grams in sodium in 7.6g of Na2C6H6O7 (sodium hydrogen citrate) express your answer using two significant

Katen [24]

Answer:

Explanation:

the molecular mass of Na2C6H6O7 =236 g\mole it has a sodium that has 23 g/mole so 7.6 g of Na2C6H6O7 has x of sodium mass

236 g/mole ⇒ 23g/mole

7.6 x 23 ÷ 236 = 74.07×10-2 grams of sodium

<h2 />

7 0

3 years ago

A sucrose solution is prepared to a final concentration of 0.250 M . Convert this value into terms of g/L, molality, and mass %.

MArishka [77]

Answer:

A. 85.6 g

= 0.0856 kg.

B. 0.00027 mol/g

= 0.27 mol/kg.

C. 8.39 %

Explanation:

Given:

Molar concentration = 0.25 M

Molar weight of sucrose = 342.296 g/mol

Density of solution = 1.02 g/mL

Mass of water = 934.4 g.

Density in g/l = 1.020 g/ml * 1000ml/1 l

= 1020 g/l

Mass of solution in 1 l of solution = 1020 g

Mass of solution = mass of solvent + mass of solute

Mass of sucrose = 1020 - 934.4

= 85.6 g of sucrose in 1 l of solution.

Density of sucrose = mass/volume

= molar mass/molar concentration

= 342.296 * 0.25

= 85.6 g/l

Number of moles = mass/molar mass

= 85.6/342.296

= 0.25 mol

Molality = number of moles of solute/mass of solvent

= 0.25/934.4

= 0.00027 mol/g

% mass of sucrose = mass of sucrose/total mass of solution * 100

= 85.6/1020 * 100

= 8.39 %

6 0

3 years ago