Answer:
Explanation:
If two forces act on an object in the same direction, the net force is equal to the sum of the two forces.
Kinetic energy is formed when water is heated.
Explanation:
- Suppose in an electric kettle there is water , when water is boiled the electrical energy changes into thermal energy when heating is done.
- The thermal energy then gets transferred to the water . When the boiling takes place in the water the energy gets transformed into sound.
- Lastly at the end the gravitational potential energy finally changes to the kinetic energy.
Answer: Option (B) is the correct answer.
Explanation:
It is advised that while conducting an experiment in a laboratory, always perform it under the supervision of your teacher.
When Hiro accidentally touches the liquid then he should immediately tell his teacher about it so that timely precaution can be taken to avoid any damage or side effect. Also, Hiro should rinse his hand in the sink because it will neutralize or decrease the effect of spilled liquid on his skin.
Thus, we can conclude that he should tell his teacher about the spill and rinse his hand in the sink.
Answer:
Periods indicate that a new period at a new principal energy level which is filled with electrons. Groups indicate that the elements share similar properties because their shells are filled with the same number of valence electons.
Explanation:
e see that starting at period 2 Li has a +1 charge , He has +2 charge, B has +3 charge, C has the potential to have a +4 charge or -4 charge (because it can gain or loose electrons) and N has a -3 charge, etc. Groups however, have similar properties and every element in a 1A - 8A has the same number of valence electrons. All except the noble gases in which He only needs 2 electrons to be in a perfect state. This is its octet as it would be a completely different element if it had more than 2 electrons in its shell. An example of the groups sharing similar properties is if we were to look at group 1A. In group 1A we find H, Na, K, etc. These are all highly unstable elements when alone (not in a compound) and they are very reactive. If you were to put Na for instance in water, it would light up and you'd see a flame sitting on top of the water. A scientist could do that with the rest of the elements in the group and they would see this increasing in reactivity as you go down the periods. Francium isn't visible long enough to be able to see this happen though. It's more of that kind of element that scientists prove that it exists, but not a very common element to get to learn much about.
This actually means that the object which is emitting light spectrum is moving away from us.. how do you know that ? well.. it is clearly mentioned that it is a red shift so the wavelengths will stretched more . and thus the spectrum turns more reddish as it has higher wavelengths .. hence so called red shifts