Yeah yeah so :D,
Large polar molecules can only cross the membrane with the help of protein named channel protein and carrier protein.
So, this both proteins act like a gate, the large molecules enter the protein and the protein let the large molecules in to the membrane. (see the picture so that you can understand more, its carrier protein)
the only difference between channel protein and carrier protein is, channel proteins has fixed shape while carrier protein can flip.
Answer:
5g/cm³
Explanation:
Given parameters:
Mass of the metal = 10g
Volume of the metal = 2cm³
Unknown:
Density of the metal = ?
Solution:
Density is the mass per unit volume of a substance.
Mathematically;
Density = 
Insert the parameters and solve;
Density = 
= 5g/cm³
D) The Earth was hit by a one or more objects from space 65 million years ago. The iridium layer shows an extraterrestrial cause for the extinction at the Cretaceous Tertiary boundary, discovered by the Alvarez family. The first discovery of this layer was in the Bavarian alps, in Lattengebirge. The Alverez family proposed that the extinction of the dinosaurs was due to a large meteor hitting the Earth at the end of the Cretaceous period, marking the KT boundary with this clay layer which has a high content of iridium. Iridium is not common on Earth, but is common in meteors.
Penicillin was made to help soldiers
