The element in period 4 and group 1 of periodic table is potassium which is a metal.
An element is said to possess metallic properties if it has 1,2,3 electrons in its valence shell as these number of electrons can be easily removed by supplying less amount of energy .
Elements present in group 1,2,3 have 1,2,3 valence electrons respectively.Hence, these elements are metals and it is a characteristic property of metals to easily loose electrons.
Hence group 1, 2 are metals which comprises the s-block of the periodic table.Metallic properties increases down the group as distance between valence electrons and nucleus increases due to which they can be easily removed.
Metallic propertiesdecrease along a period as electrons are added to same shell and hence cannot be easily removed.
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Answer:
NO: A and B
YES: C and D
Explanation:
A. Atomic Number No. This is the number of protons in the nucleus.
B. Molecular Weight No. Protons + Neutrons
C. Chemical Reactivity Yes. The electron configuration allows prediction of reactivity with other elements.
D. Valence Electrons Yes. The most active electrons is bonding.
In every day life work is a job while in scientific terms the work is a change in energy due to applied force and displacement.
Work(Job) -
In every day life, work means an specific job that is assigned to people.
For example: I work as account assistant in the company.
Work:
In scientific terms the work is a product of applied force and displacement. It is measured in Joule.
For example- the engine did the 10 J of work.
Therefore, in every day life work is a job while in scientific terms the work is a change in energy due to applied force and displacement.
To know more about Work,
Answer: Option (4) is the correct answer.
Explanation:
Atomic mass of an atom or element means the total number of protons and total number of neutrons present.
Whereas atomic number means the total number of protons present in an atom or element.
In period 5 on the Periodic Table, elements from left to right are arranged in order of increasing atomic number.
On the other hand, the atomic mass is not increasing from left to right.
(2) pressure (4) chemical energy
Answer: The correct answer is Option (1).
Explanation:
Average kinetic energy is defined as the average of the kinetic energies that is associated to the particles of the sample which are in random motion.
Temperature is the measure of the average kinetic energy of the particles. Formula used for calculating the average kinetic energy is given by:
where,
K = kinetic energy
R = Gas constant
= Avogadro's constant
T = temperature
Kinetic energy is directly proportional to the temperature of the particle.
As the temperature increases, the kinetic energy of the particles also increases and vice-versa.
Hence, the correct answer is option 1.
a. True
b. False
This statement is FALSE. Mercury was not first discovered in the sun. In fact, mercury or quicksilver was discovered by ancient Indians and Chinese even before 2000 BC. Its ores that are called cinnabar are used in traditional Chinese medicines. However, the effectiveness is not yet justified because of the toxicity of the element. Mercury is also used with thermometers both in clinical and lab uses. Nowadays, the use of it in thermometers is gradually disappearing because of its harmful properties.