Answer:
c
Explanation:
we have only distance vs time graph so c is the right answer that cart is moving with constant speed of 0.5m/s
confirmed
first calculate distance which is from 2 to 5.5
5.5-2=3.5
apply the formula of velocity
v=s/t
v=3.5/7=0.5
You can use a graduated cylinder.
Answer: The empirical formula for the given compound is 
Explanation : Given,
Percentage of C = 38.8 %
Percentage of H = 16.2 %
Percentage of N = 45.1 %
Let the mass of compound be 100 g. So, percentages given are taken as mass.
Mass of C = 38.8 g
Mass of H = 16.2 g
Mass of N = 45.4 g
To formulate the empirical formula, we need to follow some steps:
Step 1: Converting the given masses into moles.
Moles of Carbon =
Moles of Hydrogen = 
Moles of Nitrogen = 
Step 2: Calculating the mole ratio of the given elements.
For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 3.23 moles.
For Carbon = 
For Hydrogen = 
For Oxygen = 
Step 3: Taking the mole ratio as their subscripts.
The ratio of C : H : N = 1 : 5 : 1
Hence, the empirical formula for the given compound is 
Principal quantum number is n = 2, principal quantum number gives the energy shells electrons reside in,
angular momentum quantum number , these are the number of subshells and gives how many subshells are there in energy shells, values for l range from 0 to n-1
magnetic quantum number -m- gives the specific orbital in the subshells and their orientation.
spin quantum number gives the spin of the electrons.
in this case, n = 2
the types of subshells in n=2 are 0 and 1
0 - s subshell
1 - p subshell
the specific number of orbitals are given by -l to +l
when l = 1
then -1, 0 and +1
therefore there are 3 orbitals in p subshell and orbitals are in 3 orientations
each orbital can hold a maximum of 2 electrons,
since there are 3 orbitals each holding 6, there are 6 electrons to which these quantum numbers are the same
answer is 6