Answer:A double convalescent bond is where two pairs of electrons are shared between the atoms rather than just one pair. Two oxygen atoms can both achieve stable structures by sharing two pairs of electrons as in the diagram.
Explanation:
Answer:
4. 1; 6; 2 — synthesis
Explanation:
<u>Decomposition reaction </u>is defined as the reaction in which a single large substance breaks down into two or more smaller substances.

<u>Single displacement </u>reaction is defined as the reaction in which more reactive element displaces a less reactive element from its chemical reaction.
The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.

<u>Synthesis reaction</u> is defined as the reaction in which smaller substances combine in their elemental state to form a larger substance.

The unbalanced combustion reaction is shown below as:-
On the left hand side,
There are 4 phosphorus atoms and 1 calcium atom
On the right hand side,
There are 2 phosphorus atoms and 3 calcium atoms
Thus,
Right side,
must be multiplied by 2 to balance phosphorus.
Left side,
is multiplied by 6 so to balance the whole reaction.
Thus, the balanced reaction is:-
Thus, answer:- 4. 1; 6; 2 — synthesis
1. ocean-> seashells -> limestone -> lithosphere
2. ocean -> marine plants -> sediments -> lithosphere
A barometer measures air pressure.
Answer : The characteristic properties of a substance always remains the same irrespective of the sample being observed is large or small.
Few examples of characteristic properties of any substances includes freezing or melting point, boiling or condensing point, density, viscosity and solubility. They are specific for specific substances and which makes them easily recognizable.
Whereas chemical properties are specific for one substance which chemically transformed into another substances.