When a barium atom loses two electrons it becomes a positive ion and its radius decreases. Barium (Ba) has atomic number 56 so it has 2 electrons in first shell of an atom to become stable according to duplet rule. Then other 52 electrons revolve in the shells according to octet rules.
Another 2 electrons are in the outermost shell. To become stable electrons lose to form barium ions (Ba+2). Hence, by losing 2 electrons the outermost shell will be diminished so its radius decreases and by losing electrons it becomes positive ions.
Answer:
The correct answer is option 3, It becomes a positive ion and its radius decreases
Explanation:
As per the Octet rule, Barium has 2 electrons in its outermost shell. When it loses the two electron it gains two positive charge i.e Ba2+. As the barium loses the two electron from its outermost shell, the outermost shell becomes vacant and thus is no more considered as a part of atomic geometry of the barium atom and since the outermost shell is considered negligible the radius of barium atom reduces automatically.
because of the metling point of metals, it is difficult to just simply put metal together and have them to stay together without any type of glue or epoxy based creams.
wielding is used to melt the surface or even change the compound completely so they are able to combine with other metals.
same thing with atoms, you need a lot of heat, and speed to simply make salt or even copper because of the elements not really being favorable of each other.
b. external diffraction.
c. total internal reflection.
d. interference
Answer:
(C) Total internal reflection
Explanation:
Total internal reflection :
So the option (c) is the correct option
colloid
solution
compound
element
Answer:
colloid
Explanation:
b. dew
c. groundwater
d. surface runoff
Answer:
The answer is B. Dew Hopefully this helps!
By definition, the correct answer is option D. Scientists can identify an element by looking at the structure of a single atom because the number of protons can be determined, and thus its identity.
All atoms are composed of a central nucleus in which there are particles with a positive electric charge, the protons, and neutron, which is an electrically neutral subatomic particle, around which other particles with a negative electric charge that are electrons move.
Thus, the atom is electrically neutral, since the positive charge of the protons is compensated by the negative charge of the electrons.
Atoms of different elements have different amounts of protons. The atomic number (which is identified by the letter Z) indicates the amount of protons that is present in the nucleus of an atom.
This number is then responsible for defining the electronic configuration of the atom and the chemical properties of the element. Then it is possible to say that the number of protons in the nucleus, that is to say the atomic number Z, of an atom determines its identity.
Finally, the correct answer is option D. Scientists can identify an element by looking at the structure of a single atom because the number of protons can be determined, and thus its identity.
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Answer is: Democritus.
Democritus (c.460 — c.370 BC) was an Ancient Greek philosopher.
According to his atomic theory:
1) everything is composed of atoms.
2) atoms are physically indivisible
3) there is empty space between atoms.
4) atoms are indestructible and in motion.
5) there is an infinite number of atoms, which differ in shape and size.
Democritus was the first to propose the existence of atoms. Option A is the correct answer.
Thus, In contrast to the outdated idea that matter might be divided into any arbitrarily small quantity, atomic theory argues that matter is formed of discrete units called atoms.
It was first introduced as a philosophical idea by Democritus in ancient Greece and India, and it later became a widely accepted scientific theory. Chemical advancements at the time demonstrated that matter did indeed behave as if it were composed of particles.
A fundamental physical quality of matter is mass. The term "atomic mass" refers to the weight of an atom or molecule. To determine the average mass of elements and molecules as well as to resolve stoichiometry issues, the atomic mass is used.
Thus, Democritus was the first to propose the existence of atoms.
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