A Brønsted-Lowry base is a base is a proton acceptor.
In the only case where this is done is when HCO3- accepts a proton and becomes H2CO3.
In the other cases, HCO3- is donating a proton which makes it an acid.
Sharing of electrons always means its a covalent bond, and unequal means it is polar, so it is a polar covalent bond
Answer:
1 g
Explanation:
The half-life of Am-242 (16 h) is the time it takes for half of it to disappear.
We can make a table of the mass left after each half-life.

The mass remaining after 48 h is 1 g.
Hydrogen is composed of H atom and oxygen is composed of O atom. For water, it is composed by both H and O atom. If you burn hydrogen in oxygen, you can get water. And if you electrolysis water, you can get hydrogen and oxygen.