Answer:
Explanation:
The atomic radius of elements are used to estimate the sizes of elements. The atomic radius is taken as half of the inter-nuclear distance between two covalently bonded atoms of non-metallic elements or half of the distance between two nuclei in the solid state of metals.
To solve this problem we will obtain the atomic radius values of the given elements from a standard atomic radius table;
Si 111 pm
P 98 pm
Cl 79 pm
S 87pm
pm = picometer
We see that chlorine has the least atomic radius
Explanation:
A chemical reaction is defined as the reaction in which bonds between the reactants either break or form which leads to the formation of a new substance.
For example, 
So, when we drop a sodium metal into water then it produces a frizzing sound which shows the metal is reacting with water.
We know that when two aqueous solutions chemically react with each other then it may lead to the formation of an insoluble substance which is known as precipitate.
This means that formation of a precipitate is also a chemical reaction.
Thus, we can conclude that following are the statements which show evidence for a chemical reaction.
- Dropping sodium metal into water produces fizzing.
- Mixing two aqueous solutions produces a precipitate.
The postulates of Dalton's theory were:
1) Elements are made of extremely small particles called atoms
2) <span>Atoms of a given element are identical in size, mass, and other properties
</span>3) <span>Atoms cannot be subdivided, created, or destroyed</span>
4) Atoms combine in whole number ratio to form compounds
5) Chemical reactions are the rearrangement of atoms
The third postulate has been disproved by modern science, in which the atom has been split and been subdivided into smaller parts such as the neutron, proton and electron, which are further subdivided into quarks, gluons, and kaons.
The second postulate was also disproved upon the discovery of isotopes.
