There are 20n nutrons in the atom k-42.
Answer:-
As we can see from the graphical data,
The distance covered by all the four runners is the same 5 km.
Among the four athletes, Athlete P covers the distance in under three hours.
It is the minimum time taken among the four athletes.
Thus Athlete P covers the 5 km distance in the minimum amount of time.
We know that speed = 
Since time taken for P is minimum, his speed is the maximum. P ran the fastest.
Time taken by Q = 4.5 hours.
Speed of Q = 
= 
= 1.1 km/ hr
Time taken by R = 6 hours.
Speed of R = 
= 
= 0.8 km/ hr
Answer:
The atomic number of burienium will be 307.
Explanation:
During positron emission proton is converted into the neutron and one electron neutrino with positron is released. It means the atomic number will be reduce by one and atomic mass remain same.
For example:
²³Mg₁₂ → ₁₁Na²³+ e⁺+ Ve
Similarly, when highlinium-308 undergoes positron emission the new element burienium is produced and the atomic number will be 307 while atomic mass remain same.
Properties of beta radiations:
Beta radiations are result from the beta decay in which electron is ejected. The neutron inside of the nucleus converted into the proton an thus emit the electron which is called β particle.
The mass of beta particle is smaller than the alpha particles.
They can travel in air in few meter distance.
These radiations can penetrate into the human skin.
The sheet of aluminium is used to block the beta radiation
Answer:
142.82 g
Explanation:
The following data were obtained from the question:
Volume of water = 12 mL
Volume of water + gold = 19.4 mL
Density of gol= 19.3 g/cm³
Mass of gold =.?
Next, we shall determine the volume of the gold. This can be obtained as follow:
Volume of water = 12 mL
Volume of water + gold = 19.4 mL
Volume of gold =.?
Volume of gold = (Volume of water + gold) – (Volume of water)
Volume of gold = 19.4 – 12
Volume of gold = 7.4 mL
Finally, we shall determine the mass of the gold as follow:
Note: 1 mL is equivalent to 1 cm³
Volume of gold = 7.4 mL
Density of gol= 19.3 g/cm³ = 19.3 g/mL
Mass of gold =?
Density = mass /volume
19.3 = mass of gold /7.4
Cross multiply
Mass of gold = 19.3 × 7.4
Mass of gold = 142.82 g
Therefore, the mass of the gold pebble is 142.82 g
Answer:
0.05263158 atm
Explanation: mmHg to Atmosphere Conversion Example. Task: Convert 975 mmHg to atmospheres (show work) Formula: mmHg ÷ 760 = atm Calculations: 975 mmHg ÷ 760 = 1.28289474 atm Result: 975 mmHg is equal to 1.28289474 atm. This is an example for how i got the answer.
