Mangenese is the element which have 25 protons
<u>Answer:</u> The number of moles of gas present is 0.276 moles
<u>Explanation:</u>
To calculate the number of moles of gas, we use the equation given by ideal gas:
PV = nRT
where,
P = Pressure of the gas = 725 mm Hg
V = Volume of the gas = 7.55 L
n = number of moles of gas = ?
R = Gas constant = 
T = Temperature of the gas = 
Putting values in above equation, we get:
Hence, the number of moles of gas present is 0.276 moles
Answer:
Four times the original amount if only one orange was used
Explanation:
We can assume that the oranges all have equal voltages. Connecting them in series will have an increasing effect on the voltage delivered. In our case, this will produce 4 times the voltage of the circuit when only one orange is used.
Whenever simple cells are connected in series, the voltages of the individual cells are added up to form the voltage of the whole circuit.
Let us assume that the voltage of each of the oranges is approximately 0.9 volts. The Voltage produced when the 4 oranges are joined in series is 0.9 + 0.9 + 0.9 + 0.9 = 3.6 volts
<u>Answer:</u>
Pyrite leaves behind a green-black streak when it is rubbed against an unglazed porcelain plate as a part of the streak test process.
<u>Explanation:</u>
Different minerals produce different coloured streaks when rubbed against a white ceramic or porcelain streak plate. This streak test is done to identify the mineral and distinguish the same from other minerals that look similar in colour and texture.
It must be ensured that the test is done on clean and fresh specimens of the mineral and that there must be no contaminants. Pyrite specimens are usually brass-yellow colour but it leaves a green-black streak when the streak test is done.
