Answer:
A. Peroxide breaking down into water and oxygen
Explanation:
Generally when it comes to changes, there are physical and chemical changes. In physical changes, there are no new substances been formed, however in chemical change new substances are formed.
A. Peroxide breaking down into water and oxygen
This is a chemical change.
B
. Bubbles forming when a pot of water is heated
This is a physical change
C. A pair of jeans soaked in water drying after hanging outside
This is a physical change
D
. A block of ice decreasing in size due to a change in temperature
This is a physical change.
Only option A is different from the rest,hence this is the answer.
The chemical equation is
Cu(s) +4HNO3(aq) ⇒ Cu(NO3)2(aq) + 2NO2(g) + 2H2O(g)
Answer:
12
Explanation:
In the right hand side of the equation, there are three compound which contains O2, which are;
Cu(NO3)2 , number of oxygen atoms =3*2 =6
2NO2, number of oxygen atoms = 2*2=4
2H2O, number of oxygen atoms =2*1=2
Total number of oxygen atoms on the right side of equation = 6+4+2 =12
Answer
:
Flammable substances
Explanation
:
<em>Flammable substances</em> will catch fire and continue to burn when they contact an ignition source like a spark or a flame.
For example, <em>methanol</em> is a flammable liquid.
A flammable solid may also catch fire through friction. <em>Matches</em> are flammable solids.
<span>Carbon must share 4 electrons total with the the two Oxygen atoms in order to fill it's outer electron shell, and each Oxygen atom must share 2 electrons with the Carbon atom to fill their electron shells. Therefore, in total 8 electrons must be shared (4+2+2=8)</span>
The two ways to make a saturated solution are 1 reducing the temperature of the solution and Adding more solute.<span> </span>
