Answer:
Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color chage, formation of a precipitate, formation of a gas, odor change, temperature change.
Explanation:
Speed is a derived term that is the result when distance or displacement is divided by unit time. Speed is a scalar unit which means it only includes magnitude not direction, thus always positive. The answer thus are the three choices given above.
Answer is in the question :)
Answer:
The two chairs and those sitting on them will move in nearly opposite directions at almost the same speed (assuming that the wheels can only move into two directions - front or back and assuming that the weight of both people are almost the same)
Explanation:
Newton's Third Law states that If an object X exerts a force on object Y, then object Y must exert a force of equal magnitude and opposite direction back on object X.
In other words, when force is applied from source A at B and in direction of B, B also simultaneously returns the force on B and in the direction of B.
This law applies when we jump off the ground when a rocket takes off from the earth into space, etc.
While standing, the body pushes on the earth with a force equal to its own weight. If the ground underneath the body does not meet that force in an equal and opposite direction, both standing on the earth will fall into the earth, with the earth caving underneath it.
You can see why it is important to have a strong foundation for a building and why the depth and strength of the foundation will depend on how much weight is going on it.
Cheers!
Answer:
Semi conductors are part of the fourth group in periodic table.
Explanation:
Periodic table is the arrangement of chemical elements on the basis of their atomic number. So all the elements with respective valence electrons are placed in thir respective groups. . All the elements with valence electrons four are placed in the fourth group .Semi conductors is the common name given to the elements of 4th group. These elements dont have the tendency to either donate or accept.
The group 3 elements have three electrons in their valence shell and hence have a tendency to donate. Whereas the group 5 elements having five valence electrons accept to satisfy thir octet. The semi conductors exist between 3rd and 5th groups exhibiting different properties according to the temperatures and excitations provided.
