Answer:
molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.
Answer:
Bubbles will be formed when two solutions will be combined.
Explanation:
When the solution containing
and
as a solute will be combined, the reaction will be as follows,

As a result of combination of the two solutions bubbles will be formed which will depict the evolution of carbon dioxide gas.
The answer: Periods form horizontal rows, groups form vertical columns
Explanation:
The horizontal rows on the periodic table are called periods, while the verticals columns are called groups. Elements that are in the same group have similar properties. For example Group 1 is called the alkali metals. These are all soft, reactive metals.
Answer:
B
Explanation:
four electron in atom in cal
Copper is formed of copper atoms, which are closely clustered together. If observed closely, one could witness the movement of electrons between the atoms of the copper. Each copper atom turns into a positive ion by losing one electron. Thus, copper is a lattice of positive copper ions with the movement of free electrons among them.
Due to movement of electrons freely through the metal, they are also known as conduction electrons. The presence of these conduction electrons makes the copper a good conductor of electricity and heat.