Answer:
(a) (i) All the elements of a group have similar chemical properties because they have same no. of valence electrons in their outermost shell. (ii) All the elements of a period have different chemical properties because they have different no. of valence electrons in their atoms.
Answer : The fuel value and the fuel density of pentane is, 49.09 kJ/g and 
respectively.
Explanation :
Fuel value : It is defined as the amount of energy released from the combustion of hydrocarbon fuels. The fuel value always in positive and in kilojoule per gram (kJ/g).
As we are given that:
Fuel value = 
Molar mass of pentane = 72 g/mol
Fuel value = 
Fuel value = 49.09 kJ/g
Now we have to calculate the fuel density of pentane.
Fuel density = Fuel value × Density
Fuel density = (49.09 kJ/g) × (0.626g/mL)
Fuel density = 30.73 kJ/mL =
Thus, the fuel density of pentane is
Answer : Option A) The direction the wire moves in
and Option C) the direction of the magnetic field.
Explanation : The direction of current flowing through the wire mainly depens on two factors which are i) direction of the wire moves in and ii) the direction of magnetic field.
The flow of current will occur in the direction of the wire through which it is moving in, whereas the direction of magnetic field will be in concentric circles around the direction of current passing through the wire.
Answer:
It is a satellite that collects data about rain and snow.
• Its orbit covers 90 percent of Earth's surface.
• The sensors measure microwaves.
Explanation:
Correct on edge
Answer:
the atmosphere supports life by giving us simple things like wood.
