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3 years ago

Put the following elements in order of decreasing (from largest to smallest) atomic radius: Be, Ba, F, Ca.

Chemistry

1 answer:

zhannawk [14.2K]3 years ago

6 0

Answer: Ba, Ca, Be, F

Explanation: Size of atom increases when moving down on same group

and decreases when moving on same period from left to right

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a radioactive nuclide that is used for geological dating has an atomic number of 19 and mass 40. what is the symbol of this nucl

PIT_PIT [208]

The symbol of the radioactive nuclide, given the data is ⁴⁰₁₉K

<h3>Data obtained from the question</h3>

Atomic number = 19
Mass number = 40
Symbol of nuclide =?

<h3>How to determine the nuclide</h3>

From the question given above, the atomic number of the nuclide is 19.

Comparing the atomic number (i.e 19) of the nuclide with those in the periodic table, the nuclide is potassium with a symbol of K

<h3>How to determine the symbol of the nuclide</h3>

Atomic number (Z) = 19
Mass number (A) = 40
Name of nuclide = Potassium (K)
Symbol of nuclide =?

The symbol of a nuclide is given as ᴬ₂X

Where

A is the mass number
Z is the atomic number
X is the symbol of the element

Thus,

ᴬ₂X => ⁴⁰₁₉K

Therefore, the symbol of the nuclide is ⁴⁰₁₉K

Learn more about composition of atoms:

brainly.com/question/886387

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3 0

2 years ago

How many moles of mercury are produced if 24.5 moles of mercury (II) oxide decompose?

aev [14]

Answer:

24.5 moles of mercury are produced

Explanation:

The descomposition of mercury(II) oxide, occurs as follows:

2HgO → 2Hg + O₂

<em>Where 2 moles of HgO produce 2 moles of Hg</em>

<em />

In other words, the ratio of descomposition of HgO/Hg is 2/2 = 1:1

That means, if 24.5 moles of mercury(II) oxide descompose:

<h3>24.5 moles of mercury are produced</h3>

4 0

3 years ago

PLEASE HELP!! WILL REWARD BRAINLIEST!!!

Irina-Kira [14]

Oxidation number of sulphur in S is 0, in SCl2 is +2, in SO3 is +6, in H2S is - 2, in S2Cl2 is +1, in H2SO4 is +6.

<h3><u>Explanation</u>:</h3>

Oxidation number is the numeric representation of the charge of the particular atom in a compound assuming the compound is 100% ionic in character. This oxidation number is calculated based on the electronegativity of the participating atoms and the valemct of the atoms.

In S, there are no other atoms except sulphur. So its an elemental atom and elemental atoms have oxidation number of 0.

In SCl2, chlorine is more electronegative than sulphur, so chlorine is given - 1 based on its valency and electronegativity. So sulphur will have the oxidation number of +2.

In SO3, oxygen is more electronegative than sulphur, so given - 2 based on its valency and electronegativity. So sulphur will be +6.

In H2S, hydrogen is electropositive than sulphur, so given +1. So the oxidation number of sulphur will be - 2.

In S2Cl2, chlorine is more electronegative than sulphur, so chlorine is given - 1 based on its valency and electronegativity. So sulphur will have the oxidation number of +1.

In H2SO4, hydrogen is electropositive than sulphur, so given +1 and oxygen is more electronegative than sulphur, so given - 2. So oxidation number of sulphur will be +6.

6 0

4 years ago

Please help me with this question

Leviafan [203]

1. The resulting concentration will be 0.00044 mol/L

2. The minimum mass of sodium sulfite to add will be 0.4032 grams.

<h3>Stoichiometric problems</h3>

1. Using m1v1=m2v2

m1 = 0.01 mol/L, v1 = 20 mL, v2 = 450 mL

m2 = m1v1/v2 = 0.01 x 20/450 = 0.00044 mol/L

2. $Na_2SO_3 + Ca(NO_3)_2 --- > 2NaNO_3 + CaSO_3$

Mole ratio of the reactants = 1:1

Mole of 80 mL, 0.0400 mol/L Ca(NO3)2 = 80/1000 x 0.0400 = 0.0032 mol

Equivalent mole of Na2SO3 = 0.0032 moles

Mass of 0.0032 moles Na2SO3 = 0.0032 x 126 = 0.4032 grams

Thus, the minimum mass of sodium sulfite to be added must be 0.4032 grams.

More on stoichiometric calculations can be found here: brainly.com/question/27287858

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8 0

2 years ago

What volume does 1.5 x 10^24 molecules of CO2 occupy at STP?

Nookie1986 [14]

Answer:

The volume occupied by given molecules of carbon dioxide at STP is 55.86 L.

Explanation:

$N=n\times N_A$

Where:

N = Number of particles / atoms/ molecules

n = Number of moles

$N_A=6.022\times 10^{23} mol^{-1}$ = Avogadro's number

We have:

N = $1.5\times 10^{24}$

n =?

$n=\frac{N}{N_A}=\frac{1.5\times 10^{24}}{6.022\times 10^{23} mol^{-1}}$

n = 2.4909 moles

Using ideal gas equation:

PV = nRT

where,

P = Pressure of carbon dioxide gas = $1 atm$ (at STP)

V = Volume of carbon dioxide gas = ?

n = number of moles of carbon dioxide gas =2.4909 mol

R = Gas constant = 0.0821 L.atm/mol.K

T = Temperature of carbon dioxide gas = 273.15 K (at STP)

Putting values in above equation, we get:

$V=\frac{2.4909 mol\times 0.0821 atm L/mol K\times 273.15 K}{1 atm}$

V = 55.86 L

The volume occupied by given molecules of carbon dioxide at STP is 55.86 L.

7 0

3 years ago