Answer:
electrons
Explanation:
When elements combine to form compounds, chemical bonds form between the atoms. Bonds form when atoms share or exchange electrons in a way that gives each atom a complete outer shell.
For example:
Ionic bond:
It is the bond which is formed by the transfer of electron from one atom to the atom of another element.
For example:
Sodium chloride is ionic compound. The electronegativity of chlorine is 3.16 and for sodium is 0.93. There is large difference is present. That's why electron from sodium is transfer to the chlorine. Sodium becomes positive and chlorine becomes negative ion. Both atoms are bonded together electrostatic attraction occur between anion and cations and have complete octet.
Covalent bond:
It is formed by the sharing of electron pair between bonded atoms.
For example:
In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive. Both have complete octet.
Labels images and descriptions
Answer:
Option a.
Explanation:
The transformation of a solid into liquid is a slow process, hence a rate of heating too fast, near the melting point of the sample, will not give the right time to the crystals of the sample to absorb the heat and to melt in the outside and the inside, leading to wrong results in all cases. If we heat to fast, the melting point range will be too broad and will be misleading, resulting in values of the range more hight than the theoric ones.
A rate of 1 °C/min or 2 °C/min is the most appropriate to approach the melting point of the sample. Since it is too slow, from preventing the experiment taking forever it is recommended to start the experiment at a high heating rate until it reaches 20 °C below the melting point, and then, turn the heating rate down to 1 °C/min or 2 °C/min.
Therefore, the correct answer is a: near the melting point of the sample, we must heat slowly until it reach the expected temperature.
I hope it helps you!
Answer:
B The cells of the body use the oxygen to release the energy from the food.
Explanation:
Good Luck!
