Boron is a non metal why
1 answer:
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Answer:
Density, melting point. and magnetic properties
Explanation:
I can think of three ways.
1. Density
The density of Cu₂S is 5.6 g/cm³; that of CuS is 4.76 g/cm³.
It should be possible to distinguish these even with high school equipment.
2. Melting point
Cu₂S melts at 1130 °C (yellowish-red); CuS decomposes at 500 °C (faint red).
A Bunsen burner can easily reach these temperatures.
3. Magnetic properties
You can use a Gouy balance to measure the magnetic susceptibilities.
In Cu₂S the Cu⁺ ion has a d¹⁰ electron configuration, so all the electrons are paired and the solid is diamagnetic.
In CuS the Cu²⁺ ion has a d⁹ electron configuration, so all there is an unpaired electron and the solid is paramagnetic.
A sample of Cu₂S will be repelled by the magnetic field and show a decrease in weight.
A sample of CuS will be attracted by the magnetic field and show an increase in weight.
In the picture below, you can see the sample partially suspended between the poles of an electromagnet.
The question is incomplete, here is the complete question:
Classify each element. Note that another term for main group is representative, another term for semi-metal is metalloid, and the inner transition metals are also called the lanthanide and actinide series.
Hf, Am, In, Ta, As, Se, Rn
<u>Answer:</u>
Hafnium and tantalum are transition elements.
Americium is a inner transition element.
Indium, Selenium and Radon are main group elements.
Arsenic is a metalloid.
<u>Explanation:</u>
Main group elements are the elements which belong to s block and p block. They are also known as representative elements.
S-block elements are defined as the elements whose last electron enters s-sub shell. The general electronic configuration of these elements is
P-block elements are defined as the elements whose last electron enters p-sub shell. The general electronic configuration of these elements is
Metalloids are defined as the elements which show intermediate properties between metals and non-metals. There are 7 metalloids in the periodic table. They are: Boron, Silicon, germanium, Arsenic, Antimony, Tellurium and Polonium.
Transition elements are known as d-block elements. D block elements are defined as the elements whose last electron enters d sub shell. The general electronic configuration of these elements is
Inner transition elements are known as (f block) elements. (F block) elements are defined as the elements whose last electron enters (f subshell). The general electronic configuration of these elements is . They are also known as lanthanide and actinide series.
For the given elements:
- <u>Option 1:</u> Hf
Hafnium is the 72nd element of the periodic table having electronic configuration of
As, the last electron is entering the d subshell, it is a transition element.
- <u>Option 2:</u> Am
Americium is the 95th element of the periodic table having electronic configuration of
As, the last electron is entering the (f subshell), it is a inner transition element.
- <u>Option 3:</u> In
Indium is the 49th element of the periodic table having electronic configuration of
As, the last electron is entering the p subshell, it is a main group element.
- <u>Option 4:</u> Ta
Tantalum is the 73rd element of the periodic table having electronic configuration of
As, the last electron is entering the d subshell, it is a transition element.
- <u>Option 5:</u> As
Arsenic is the 33rd element of the periodic table having electronic configuration of
As, the last electron is entering the p subshell, it is a main group element. It shows an intermediate property of metal and non-metal. Thus, it is a metalloid.
- <u>Option 6:</u> Se
Selenium is the 34th element of the periodic table having electronic configuration of
As, the last electron is entering the p subshell, it is a main group element.
- <u>Option 7:</u> Rn
Radon is the 86th element of the periodic table having electronic configuration of
As, the last electron is entering the p subshell, it is a main group element.