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3 years ago

What determines the order of placement of the elements on the modern Periodic Table?

2 answers:

3 0

The order of placement of the elemnts on the modern Periodic Table is determinated by:
1)atomic number (Z=number of protons).

Rashid [163]3 years ago

3 0

The periodic table was and still is arranged in increasing atomic number, aka number of protons.

Answer: <span>1.atomic number</span>

You might be interested in

Why do you think the molarity relationship is so important to the chemist?

Oksana_A [137]

There are two big advantages of using molarity to express concentration. The first advantage is that it's easy and convenient to use because the solute may be measured in grams, converted into moles, and mixed with a volume.

The second advantage is that the sum of the molar concentrations is the total molar concentration. This permits calculations of density and ionic strength

5 0

2 years ago

Why are only certain colors absorbed by and emitted from an atom?

zavuch27 [327]

The way I would explain it is quite difficult to understand, so this is what Google says. "The wavelength (or equivalently, frequency) of the photon is determined by the difference in energy between the two states. These emitted photons form the element's spectrum. The fact that only certain colors appear in an element's atomic emission spectrum means that only certain frequencies of light are emitted." I hope this helped.

6 0

3 years ago

HELPPPP PLEASEEE

Igoryamba

Atomic mass is the answer!!
Explanation: An elements atomic number won’t be able to change

6 0

2 years ago

What pressure is required to compress 156.0 liters of air at 2.00 atmosphere into a cylinder

garik1379 [7]

Answer:

option B.

Explanation:

Given,

V₁ = 156 L

P₁ =2 atm

Now, in the cylinder

P₂ = ?

V₂ = 36

Using relation between pressure and volume

$\dfrac{P_1}{V_2}=\dfrac{P_2}{V_1}$

$\dfrac{2}{36}=\dfrac{P_2}{156}$

$P_2 = 8.67\ atm$

Hence, pressure is equal to 8.67 atm.

Hence, the correct answer is option B.

7 0

3 years ago

A sample of gas is observed to effuse through a pourous barrier in 4.98 minutes. Under the same conditions, the same number of m

kogti [31]

Answer:

The molar mass of the unknown gas is $\mathbf{ 51.865 \ g/mol}$

Explanation:

Let assume that the gas is O2 gas

O2 gas is to effuse through a porous barrier in time t₁ = 4.98 minutes.

Under the same conditions;

the same number of moles of an unknown gas requires time t₂ = 6.34 minutes to effuse through the same barrier.

From Graham's Law of Diffusion;

Graham's Law of Diffusion states that, at a constant temperature and pressure; the rate of diffusion of a gas is inversely proportional to the square root of its density.

i.e

$R \ \alpha \ \dfrac{1}{\sqrt{d}}$