Answer:
Explanation:
Ionic bond:
It is the bond which is formed by the transfer of electron from one atom to the atom of another element.
Both bonded atoms have very large electronegativity difference. The atom with large electronegativity value accept the electron from other with smaller value of electronegativity.
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 joint together by electrostatic interaction and ionic compound sodium chloride is formed.
Covalent bond:
It is formed by the sharing of electron pair between bonded atoms.
The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.
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 and both bonded atoms connected together through covalent bond.
The number of protons is same as periodic table number.
In this case 81 Periodic table number element has 81 Protons.
Apples turnjng brown when left in air
Answer:
474.64mmHg
Explanation:
From the question given, we obtained the following:
V1 = 10L
P1 = 655mmHg
V2 = 13.8L
P2 =?
P1V1 = P2V2
10 x 655 = P2 x 13.8
Divide both side by the coefficient P2 i.e 13.8
P2 = (10 x 655) / 13.8
P2 = 474.64mmHg
Therefore, the new pressure will be 474.64mmHg
We can observe physical properties of elements and compounds without changing the substance.
Examples of physical properties: Density, color, boiling point, state of matter, appearance: dull or shiny, etc.
But we can also observe and measure chemical properties by reacting a substance with something else. For example, like mixing baking soda and vinegar together. The vinegar reacts with the baking soda and produces carbon dioxide: a new substance.
Some examples of chemical properties: Flammability, amount of heat that is released during combustion, toxicity (how much damage it causes to other organisms), radioactivity, and ability to oxidize (when you have metal that becomes rusty looking).