Answer:
0 kgm/s
Explanation:
The momentum of Bob while resting at the river is 0 kgm/s.
This is because the momentum of any object at rest is 0.
Momentum is the quantity of motion a body contains. It is mathematically expressed as;
Momentum = m x v
m is the mass
v is the velocity
So at rest, the velocity of a body is 0m/s and therefore, the momentum is O
Answer:
1s² 2s²2p³
Explanation:
If the atom has seven electrons, it is Element 7 (nitrogen).
In the Periodic Table, you count the electrons in all the subshells up to
No. 7.
In the first Period, you have filled the 1s level (2 electrons).
In the second Period, you have filled the 2s subshell (2 electrons) and put three electrons in the 2p subshell.
Thus, the electron configuration is
1s² 2s²2p³
Note how the superscripts tell you the number of electrons in each subshell: <em>2 + 2 + 3 = 7</em>.
Answer: 17 years
Explanation:
Expression for rate law for first order kinetics for radioactive substance is given by:

where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.


b) for 8900 g of the mass of the sample to reach 7700 grams


Thus it will take 17 years
Answer:
iron oxide11
Explanation:
iron oxide is the chemical compound with formula fe304. it occurs in nature as the mineral magnetite.
all i really know is that STP (standard temperature and pressure) represents conventional conditions established by IUPAC with T = 273.15 K, P = 1 atm . Now putting these values of temperature and pressure at STP, we can calculate easily volume occupied by 1 mol of gas and which comes out to be 22.4 L. hope this helps