Answer:
B. electrons and protons.
Explanation:
In an electrically neutral atom of any element, there are equal number of protons and electrons in the atom.
Protons are the positively charged particles in an atom.
Electrons are the negatively charged particles within the atom.
When the number of protons and electrons are the same or equal, the atom is neutral.
But when there is an imbalance, an ion results.
Answer:
A free body diagram is used to calculate static and dynamic forces acting on an object. In other words, a free body diagram is the starting point to develop a mathematical model to find and calculate various forces acting on a body.
Explanation:
Answer:
A.......
Explanation: The sun is the main source of energy
Answer:
Wide melting point range - impure sample with multiple compounds
Experimental melting point is close to literature value - pure sample of a single compound
Experimental melting point is below literature value - impure sample with multiple compounds
Narrow melting point range - pure sample of a single compound
Explanation:
The melting point of substances are easily obtainable from literature such as the CRC Handbook of Physics and Chemistry.
A single pure substance is always observed to melt within a narrow temperature range. This melting temperature is always very close to the melting point recorded in literature for the pure compound.
However, an impure sample with multiple compounds will melt over a wide temperature range. We also have to recall that impurities lower the melting point of a pure substance. Hence, the experimental melting point of an impure sample with multiple compounds is always below the literature value.
