Answer:
Cohesion
Explanation:
Depending on how attracted molecules of the same substance are to one another, the substance will be more or less cohesive. Hydrogen bonds cause water to be exceptionally attracted to each other. Therefore, water is very cohesive.
The rate of reaction between oxygen and copper is higher at high temperature. The rate of reaction between oxygen and copper is lower at room temperature.
at high temperature copper penny will react with oxygen as shown below

The reaction does not occur easily at room temperature
We can say that the reaction between copper and oxygen is an endothermic reaction so the rate of reaction is high at high temperature.
The bond energy of oxygen molecules need energy to react with copper and form copper oxide.
Silicon is a popular semi-conductor. The process of doping either creates an excess or lack of electrons. In the case of silicon, the dopant is arsenic which has greater valence electron than silicon. Arsenic then donates an electron resulting to an excess of electrons. A new type or better type of semi-conductor is created. Silicon conduct greater electricity.
The best answer is the last option.
First, we need to state the chemical equation for the combustion of PH3

And the mass of PH3 is 17.0 grams and we need to know the moles.
In the periodic table, the atomic mass of the P (phosphorus) is 31 and the atomic mass of the H (hydrogen) is 1.
So, you sum the mass of P to the mass of H multiplied by 3 and you obtain this:

With this data, we can search the moles of PH3:
Answer: The molecular formula is
Explanation:
We are given:
Mass of
= 0.1605 g
Mass of
= 0.0220 g
mass of
= 0.1425 g
Step 1 : convert given masses into moles.
Moles of C =
Moles of H =
Moles of S =
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C =
For H =
For S =
The ratio of C : H: S= 3: 5: 1
Hence the empirical formula is
The empirical weight of
= 3(12)+5(1)+1(32)= 73g.
The molecular weight = 146 g/mole
Now we have to calculate the molecular formula.
The molecular formula will be=