Question 4: The first one
Question 5: The fourth one
Question 6: The first one
Question 7: The third one
A chemical change is characterized of the formation of new substances or a chemical reaction. There are a number of observations that we can see if this type of change happens. One would be the formation of gas bubbles, this indicates that one of the products is a gas. Another observation would be a formation of a precipitate in the solution, it would indicate that the new solid formed is not soluble in the solution. A permanent color change in the solution would also indicate a chemical change because it may be that the new substance that is formed has its own distinct color when in solution.
Answer:
increases
decreases
Explanation:
The distance between particles increases when the temperature increases and decreases when temperature decreases.
- Temperature changes in a system causes the particle of such system to behave in different ways.
- When particles gain heat energy as their temperature increases, they begin to move further apart.
- As their temperature reduces they tend to coalesce.
For a hydrogen atom, composed of an orbiting electron bound to a nucleus of one proton, an ionization energy of 2.18 × 10−18 joule (13.6 electron volts) is required to force the electron from its lowest energy level entirely out of the atom.