Lets do process of elimination!
A. Breaking glass - That is a psychical change because if you break it, it is still glass. It didn't change to another substance.
B. Melting ice on a windshield - During the melting process, there is no chemical change, and therefore, no new substance is created.
C. Burning gasoline - When gas burns it usually combines with oxygen to give carbon dioxide, water etc. It is a chemical change.
D. Denting a bumper - The bumper is still a bumper, only thing is it has a dent in it. The properties did not change, meaning no chemical change.
Answer:
It emits 1.64 x 10⁻¹⁸J of energy
Explanation:
The n = 1 is a lower quantum level compared to n = 2.
When a hydrogen atom moves from a higher level to a lower one, it simply emits the energy difference between the two levels.
- If a hydrogen atom moves from a lower energy level to a higher one such as from 1 to 2, they absorb the energy difference to attain the new excited state.
- So, for an electron in the hydrogen atom to move from a higher energy level to a lower one, it must emit 1.64 x 10⁻¹⁸J of energy.
Answer:
Sr 2+(aq) + SO42-(aq) → SrSO4(s)
Explanation:
<u>Step 1</u>: Write a properly balanced equation with states:
K2SO4(aq) + Srl2(aq) → 2KI(aq) + SrSO4(s)
<u>Step 2</u>: write the full ionic equation with states. Remember to keep molecules intact. Only states (aq) will dissociate, (s) will not dissociate
. This means SrSO4 won't dissociate.
2K+(aq) + SO42-(aq) + Sr 2+(aq) + 2I-(aq) → 2K+(aq) + 2I-(aq) + SrSO4(s)
<u>Step 3</u>: Balanced net ionic equation
Sr 2+(aq) + SO42-(aq) → SrSO4(s)
Answer:
Phase transition is when a substance changes from a solid, liquid, or gas state to a different state. Every element and substance can transition from one phase to another at a specific combination of temperature and pressure.
Explanation:
Farmers use the property of density of cranberries to harvest the crop because an object with a density less than, in this case, water, it will float.
When farmers flood cranberry bogs with water, they know that cranberries have a density less than about 1 g/mL. Because of this, cranberries will float to the top of water and can be easily harvested.