A atomic number hope i helped
Heating the reaction flask on a hot plate is an example of supplying activation energy to begin a reaction.
Explanation:
<u>Definition:</u>
Activation energy is defined as the minimum amount of energy required to start a particular chemical reaction.
For example: When hydrogen and oxygen are mixed together it does not immediately start the reaction to form water. So, to start the reaction a small electric spark is provided or it is heated to provide some energy. This energy causes the molecules of hydrogen and water to react, thus producing even more molecules to react and finally water is formed.
Here the electric spark or the heat provided is the activation energy.
B the atmosphere
D. gasoline
C. a carbonated soft drink (without bubbles)
<h2>Work done = mgh </h2>
Explanation:
- In this case, while lifting the book we are working against the force of gravity.
Using the Newton's laws, we can find the force F required for lifting the book having mass (m) and acceleration due to gravity (g) that is ;
and, the change in the position of the book that is Δx (Height)
→ Δx = Final position - Initial position
which is only the height, then the amount of work done will be calculated by :
W= mgh
m = Mass of the Body
g = Acceleration due to Gravity
h = Height of Body being displaced
Reaction of sodium with water
Sodium metal reacts rapidly with water to form a colourless solution of sodium hydroxide (NaOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. The reaction is exothermic. During the reaction, the sodium metal may well become so hot that it catches fire and burns with a characteristic orange colour. The reaction is slower than that of potassium (immediately below sodium in the periodic table), but faster than that of lithium (immediately above sodium in the periodic table).
2Na(s) + 2H2O → 2NaOH(aq) + H2(g)
