#20 which type of bond is formed when bases pair in dna? ionic bond covalent bond coordinate bond hydrogen bond

hydrogen bond, nucleotides in a base pair complement each other which means their shape allows them to bond together with hydrogen bonds.

 Hydrogen Bond

Explanation:  The nitrogenous bases point present on onse strand og DNA form pairs with bases on the other side.

Each base pair is formed from two complementary nucleotides (purine with pyrimidine)  which are bound together by hydrogen bonds.

Thus when bases pair up in DNA , the force holding them is known to be the Hydrogen Bonds.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles