Answer:
4
Explanation:
there is a decimal place present. so you would take away any zeros before the number.
Answer:
Soil is heterogeneous mixture of sand particles of different sizes, shape and of different compositions.
Explanation:
Homogeneous mixtures are defined as the mixtures in which components are evenly spread throughout the solution. The size and shape of the particles are similar in these mixtures.
For example : alloys, salt solution.
Heterogeneous mixtures are defined as the mixtures in which component are unevenly spread throughout the solution. The size and shape of the particles differ in these mixtures.
For example : sand in a water, soil etc.
Brass is an alloy homogeneous mixture of metals.
Air is a homogeneous mixture of gases.
Coffee with sugar stirred in is also homogeneous mixture.
Soil is a heterogeneous mixture of sand particles of different sizes, shape and of different compositions.
First let us calculate for the molar mass of ibuprofen:
Molar mass = 13 * 12 g/mol + 18 * 1 g/mol + 2 * 16 g/mol
Molar mass = 206 g/mol = 206 mg / mmol
Calculating for the number of moles:
moles = 200 mg / (206 mg / mmol)
moles = 0.971 mmol = 9.71 x 10^-4 moles
Using the Avogadros number, we calculate the number of
molecules of ibuprofen:
Molecules = 9.71 x 10^-4 moles * (6.022 x 10^23 molecules
/ moles)
<span>Molecules = 5.85 x 10^20 molecules</span>
Answer:
Polar covalent bond
Explanation:
On the basis of electronegativity bond could be ionic bond, polar and non pole covalent bond.
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. The electronegativity difference between bonded atoms is greater than 1.7.
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.
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. There are two type of covalent bond. Polar and non polar covalent bond. When electronegativity difference is 0.4 - 1.7 bond is polar covalent bond when it is less than 0.4 the bond is non polar covalent.
For example:
In CO the electronegativity of oxygen is 3.5 and carbon is 2.5. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and carbon becomes partial positive. and bond is polar covalent.
