Sodium and chloride also help to determine the resting potential. Sodium is positive and has a concentration gradient set up to flow INTO the cell, and chloride is negative and has a concentration gradient set up to flow INTO the cell. The resting conductance for these two ions is less than that of potassium, but is not zero. Their story (concentration gradient + electrical gradient) is very similar to that of potassium. These ions together determine the resting potential of the cell.
1 the U.S.A. ranks number 3 in the list of countries by population. 2  The population density in the United States is 35 per Km2 (92 people per mi2). 3  The total land area is 9,155,898 Km2 (3,535,111 sq. miles) 4  82.5 % of the population is urban (268,012,791 people in 2016)  The median age in the United States is 38.1 years.
Population density (people per km 2) by country in 2015. This is a list of countries and dependencies ranked by human population density and measured by the number of human inhabitants per square kilometer or square mile. The entity is composed of 28 member countries. 2  Its population density has been estimated at 116 people per kmÂ², and it would be ranked 95th if it were included in the list. ( 3 population: 506,913,394 on January 1, 2014, area: 4,324,782 km 2). 4  See also: List of regional organizations by population.