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3 years ago

When traveling from oxygen to sulfur to selenium, through this group in the periodic table, what is changing?

2 answers:

5 0

Horizontal rows are called periods. As you travel downwards, the period is changing. (Oxygen in period 2, sulfur in period 3, and selenium in period 4)

mel-nik [20]3 years ago

4 0

Answer: The size of the element is changing.

Explanation:

Oxygen, sulfur and selenium are the elements which belong to Group 16 and periods 2, 3 and 4 respectively.

Atomic size of an element is defined as the distance between the nucleus and the outermost shell.

In a periodic table, the size of an element decreases as we move across a period and increases as we move down the group.

Down the group, new shell is getting added around the nucleus and electron is getting added in the new shell. Hence, the distance of the outermost shell from nucleus increases.

Therefore, the size of the element is changing.

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QUESTION 17

borishaifa [10]

Question 17:

False; cutting hair would change what it looks like but, braiding it keeps it the same substance it is.

Question 18 :

My best guess would either be A or D. I would lean more towards D because if there are different mixtures then it depends on what you are mixing.

Hope it helps in some way. <3

5 0

3 years ago

If the spin of one electron in an orbital is clockwise, what is the spin of the other electron in that orbital?

umka2103 [35]

Answer:

The other electron must have anticlockwise spin.

Explanation:

According to the pauli exclusion principle, the two elecrton present in same orbital must have opposite spin.

If the one electron is clockwise the other must be in anti clockwise direction. The clockwise direction is represented by the sign +1/2 while anti clockwise direction is represented by -1/2.

According the pauli principle, the two electrons must have different fourth electronic quantum number. The electron in same orbital have same first three quantum number i.e, n=1 l=0 and ml =0 in case of first subshell.

3 0

3 years ago

A 0.1 gram sample of an unknown liquid is vaporized completely at 70 degrees C to fill a 750mL flask. The pressure is 0.05951atm

Deffense [45]

Answer:

The molar mass of the liquid 62.89 g/mol

Explanation:

Step 1: Data given

Mass of the sample = 0.1 grams

Temperature = 70°C

Volume = 750 mL

Pressure = 0.05951 atm

Step 2: Calculate the number of moles

p*V = n*R*T

n = (p*V)/(R*T)

⇒ with n = the number of moles gas = TO BE DETERMINED

⇒ with p = The pressure = 0.05951 atm

⇒ with V = The volume of the flask = 750 mL = 0.750 L

⇒ with R = The gasconstant = 0.08206 L*atm/K*mol

⇒with T = the temperature = 70 °C = 343 Kelvin

n = (0.05951 *0.750)/(0.08206*343)

n = 0.00159 moles

Step 3: Calculate molar mass

Molar mass = mass / moles

Molar mass =0.1 gram / 0.00159 moles

Molar mass = 62.89 g/mol

The molar mass of the liquid 62.89 g/mol

6 0

3 years ago

If I have 2 liters of gas held at a pressure of 78 atm and a temperature of 900 k, what will be the volume of the gas if I decre

dangina [55]

Answer:

V2 = 2.88L

Explanation:

P1= 78atm, V1= 2L, T1= 900K, P2= 45atm, V2=? T2= 750K

Applying the general gas equation

P1V1/T1 = P2V2/T2

Substitute the above

(78*2)/900= (45*V2)/750

V2= (78*2×750)/(900*45)

V2= 2.88L

7 0

3 years ago

Consider the reaction. PCl5(g)↽−−⇀PCl3(g)+Cl2(g) K=0.042 The concentrations of the products at equilibrium are [PCl3]=0.18 M and

tatyana61 [14]

Answer: The equilibrium concentration of $PCl_5$ is 1.285 M.

Explanation:

The chemical equation for the decomposition of phosphorus pentachloride follows:

$PCl_5(g)\rightleftharpoons PCl_3(g)+Cl_2(g)$

The expression for equilibrium constant is given as:

$K_c=\frac{[PCl_3][Cl_2]}{[PCl_5]}$

We are given:

$K_c=0.042$

$[PCl_3]=0.18M$

$[Cl_2]=0.30M$

The concentration of solid substances are taken to be 1. Thus, they do not appear in the equilibrium constant expression.

Putting values in above equation, we get:

$0.042=\frac{0.18\times 0.30}{[PCl_5]}$

$[PCl_5]=1.285$

Hence, the equilibrium concentration of $PCl_5$ is 1.285 M.

6 0

3 years ago