Using energy from ATP, sodium-potassium pumpsactively transport ions in both directions across the membrane. 2. Some potassium channelsare open, allowing certain ions to move out of the cell through them. 3. The sodium channels are closed, preventing certain ions from entering the cell through them. 4. The concentration of sodium ionsis higher outside the cell than inside. 5. The concentration of potassium ionsis higher inside the cell than outside.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

thats how its supposed to be

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3