a)
26C5 -> 26 choices of 5 things
b)
15C1 × 11C4
c)
11C1 × 15C4
d)
11C2 × 15C2
e)
11C4
or
15C4
B. the second part of meiosis is very similar to mitosis
Gases have three characteristic properties: (1) they are easy to compress, (2) they expand to fill their containers, and (3) they occupy far more space than the liquids or solids from which they form.
1 molecule of NH3 has 3 atoms of H.
6.90*10²⁴ molecules NH3 have 3*6.90*10²⁴ =20.7*10²⁴ atoms H=2.07*10²⁵ atoms H
1 molecule H2O of has 2 atoms of H.
2.60*10²⁵ molecules of H2O have 2*2.60*10²⁵ =5.20 *10²⁵ atoms of H
2.07*10²⁵ + 5.20 *10²⁵ =7.27*10²⁵ atoms of H altogether.