Given :
Human blood should have around 1.04 kg/L platelets.
A blood sample of 4.01 milliliters is collected from a patient to be analyzed for a platelet count.
To Find :
The expected mass in grams of platelets in the blood sample.
Solution :
1 L of human blood contains 1.04 kg of platelets.
So, amount of platelets is 1 ml blood is :

Mass of platelets in 4.01 ml blood is :

Hence, this is the required solution.
Answer : The correct option is, (B) 273.15 K and 1 atm
Explanation :
STP : STP stands for standard temperature and pressure.
STP conditions :
The temperature is,
or
or 
The pressure is,
or 
The volume is 22.4 L for 1 mole of a substance.
Hence, the correct option is, (B) 273.15 K and 1 atm
Explanation:
A chemical bond which is formed in between positively charged atoms when there is sharing of free electrons in a lattice of cations is known as a metallic bond.
In a pure metal, atoms are surrounded by free moving valence electrons which move from one part of metal to another.
Thus, we can conclude that pure metals are held together by metallic bonds due to attraction between mobile valence electrons and positively charged metal ions.
ΔG⁰ = ΔH⁰ - T ΔS⁰
ΔG⁰ : Standard free energy of formation of acetylene
ΔH⁰ : Standard enthalpy of formation (226.7 kJ/mol)
ΔS⁰ : Standard entropy change (58.8 J / K. mol)
T : Temperature 25°C = 298 K (room temperature)
ΔG⁰ = 226.7 - (298 x 58.8 x 10⁻³) = 209.2 kJ /mol