Which of the following elements should be the best conductor of electricity?
Silver Conductivity “Silver is the best conductor of electricity because it contains a higher number of movable atoms (free electrons). For a material to be a good conductor, the electricity passed through it must be able to move the electrons; the more free electrons in a metal, the greater its conductivity.
Which of the following elements would you expect to be a good conductor?
Conduction: Metals are good conductors because they have free electrons. Silver and copper are the two best conductors of heat and electricity. Lead is the poorest conductor of heat. Bismuth, mercury and iron are also poor conductors.
Which elements are most likely to conduct electricity well?
Explanation : The elements likely conduct electricity well are chromium, calcium and osmium. As these are metals and are observed to be good conductors of heat and electricity. They have extra electrons to donate and hence flow of electrons cause them to be a good conductor of electricity.
Why Mendeleev left a space for the unknown?
He corrected the known atomic masses of some elements and he used the patterns in his table to predict the properties of the elements he thought must exist but had yet to be discovered. He left blank spaces in his chart as placeholders to represent those unknown elements.
How many gaps did Mendeleev leave?
Mendeleev’s periodic table is an arrangement of the elements that group similar elements together. He left blank spaces for the undiscovered elements (atomic masses, element: 44, scandium; 68, gallium; 72, germanium; & 100, technetium) so that certain elements can be grouped together.
Why did Mendeleev have problems arranging the elements?
Why did Mendeleev have problems arranging the elements Te and I? They did not fit the pattern of increasing atomic mass. Group because all of the like elements are in a group. How are the valence electrons in Lithium and Sodium different?
Why did Mendeleev’s periodic table become more widely accepted?
Mendeleev’s table became widely accepted, primarily because he predicted the characteristics and placement of elements which were yet to be discovered. One of the major developments that allowed for what became known as the periodic table was the idea of atomic mass, which is attributed to John Dalton.
Why are atomic masses no longer organized?
Assuming there were errors in atomic masses, Mendeleev placed certain elements not in order of increasing atomic mass so that they could fit into the proper groups (similar elements have similar properties) of his periodic table.
Can average atomic mass decrease even if atomic number increases?
The atomic number increases across a period and down the group or family. The atomic mass generally increases with atomic number with a few exceptions.
Why don’t we use mass number in periodic table instead of atomic mass?
Be careful you don’t confuse atomic number and mass number. While the mass number is the sum of the protons and neutrons in an atom, the atomic number is only the number of protons. The atomic number is the value found associated with an element on the periodic table because it is the key to the element’s identity.
Why is the periodic table arranged by increasing atomic number instead of increasing atomic mass?
The elements in the periodic table are arrange by atomic number which are equal to the number of protons. The chemical properties are mainly dependent on the electrons, or in some cases the charge of the protons, which is independent of the number of neutrons.So,they are arranged by increasing atomic number.
Which family of elements does not react with oxygen?
noble metals
On what basis are they arranged now?
atomic number
Which atom has the largest atomic radius?
Francium
Which is larger k or k+?
When at neutral, the potassium ion in the form of K has an electronic configuration of: The K+ ion has its outermost electrons on the third energy level now and is size is smaller than that of K ion. Hence, K is larger than K+.
Which element in group 13 has the smallest atomic radius?
Out of the following group 13 elements, element with smallest atomic radius is. Out of Al, Ga, In and Tl element with smallest atomic radius is GA.
Why does lithium have the largest atomic radius?
In lithium’s case, the outermost electron is being screened from the nucleus by two core electrons. That is why lithium has a larger atomic radius than beryllium. In fact, atomic radius decreases as you move from left to right across a period.