Why is nahco3 a base?

(i need someone to explain it using the ka values)

h2co3 < --> hco3- + h+ ka = 4.3x10^-7
hco3- < --> co3^2- + h+ ka = 5.61x10^-11

if i underestand correctly, the kb for the second equation is greater than the ka. thus the reaction will not proceed forward, but rather produce more hco3-. this is a basic tendency. why is it more powerful than the first reaction?

everyone!

Imagine that a new planet is discovered with two moons of equal mass: moon a and moon b. the mass of the new planet is greater than the combined mass of its moons. moon a is farther away from the new planet than moon b. what is the planet's gravitational pull on moon a compared to the planet's gravitational pull on moon b? the planet's gravity repels moon a with a greater force than it repels moon b, which is why moon a is farther away. the gravitational pull on moon b is greater than on moon a because moon b is closer to the new planet than moon a. the gravitational pull on moon b is greater than on moon a because moon b is farther away from the new planet than moon a. the gravitational pull on moon a is the same as the gravitational pull on moon b because distance does not affect the planet's gravity.