25. C
26. B
27. A
28. D
29. D
30. A
31. B
32. D
33. B
34. A
Group.... because elements in a group have same chemical properties
Answer:
a,b,e,f,g
Explanation:
Hydrogen bonding is an intermolecular force of attraction between two molecules. It is a special type of dipole-dipole attraction.
In hydrogen bonding, the hydrogen on one molecule binds with an electronegative atom on another molecule usually oxygen, nitrogen and fluorine.
The simple electrostatic attraction leads to strong intermolecular interaction between two molecules.
For the formation of hydrogen bond, a hydrogen atom must be bonded to more electronegative specie usually N, O and F
In H₂O and H₂O₂ ; hydrogen bonds with Oxygen
CH₃NH₂; hydrogen is attached to nitrogen
HF; hydrogen is attached to fluorine
CH₃OH; hydrogen is attached to oxygen
By adding more nutrients to it<span />
Answer: The ratio of atoms in calcium bicarbonate ; Ca : H : C : O = 1:2:2:6.
The ratio of atoms in lithium sulfide; Li : S = 2 : 1
Explanation:
In calcium bicarbonate:
In a molecular formula of calcium carbonate there are:
Number of Calcium atoms = 1
Number of Hydrogen atom = 1 × 2 = 2
Number of Carbon atoms = 1 × 2 = 2
Number of Oxygen atoms = 3 × 2 = 6
So, Ca : H : C : O = 1 : 2 : 2 : 6
In lithium sulfide :
In a molecular formula of lithium sulfide there are:
Number of Lithium atoms = 1 × 2 = 2
Number of Sulfur atoms = 1
So, the Li : S = 2 : 1
