Answer:
Magnesium
Explanation:
When an atom loses are gain the electrons ions are formed.
There are two types of ions.
Anion
Cation
1 = Anion
It is formed when an atom gain the electrons. when atom gain electron negative charge is created on atom. For example.
X + e⁻ → X⁻
2= Cation
It is formed when an atom loses the electrons. when atom lose electron positive charge is created on atom. For example.
X → X⁺ + e⁻
There are seven valance electrons in iodine. To complete the octet it gain one electron and form anion.
Sulfur has six valance electrons it gain two electrons to complete the octet and form anion.
Phosphorus has five valance electrons it gain three electrons two complete the octet and form anion.
Magnesium has two valance electrons it loses two electron to complete the octet and form cation.
Answer:
76 mmHg is the partial pressure of oxygen on this new planet.
Explanation:
Atmospheric pressure on air on earth = 760 mmHg
On an unknown planet :
Oxygen makes up 10% of the atmosphere.
The mole fraction of oxygen gas can be written as = 
Carbon dioxide makes up 15% of the atmosphere.
The mole fraction of carbon dioxide gas can be written as = 
Nitrogen makes up the remaining 75% of the atmosphere.
The mole fraction of nitrogen gas can be written as = 
Atmospheric pressure of air on unknown planet,p= 760 mmHg (given)
Partial pressure of gases can be calculated by the help o Dalton's law of partial pressure:
Partial pressure of oxygen gas :


Partial pressure of carbon dioxide gas :


Partial pressure of nitrogen gas :


It it important because it makes people wonder how things work and are made which makes it so they want to move forward with experiments <span />
Explanation:
we know that 0.250 L = 0.250 dm3
molarity = concentration in dm3/ volume
molarity = 0.175/0.250 = 0.7 mol/dm3
The change in internal energy of the combustion of biphenyl in Kj is calculated as follows
=heat capacity of bomb calorimeter x delta T where delta T is change in temperature
delta T = 29.4 -25.8= 3.6 c
= 5.86 kj/c x 3.6 c = 21.096 kj