Protons have a mass of 1
Neutrons have a mass of 1
So 13*1 + 14*1 = Mass number 27
Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom.
The term isotope is formed from the Greek roots isos ("equal") and topos ("place"), meaning "the same place".
Answer:
Radioactive isotopes ranging from 11O to 26O have also been characterized, all short-lived. The longest-lived radioisotope is 15O with a half-life of 122.24 seconds, while the shortest-lived isotope is 12O with a half-life of 580(30)×10−24 seconds (the half-life of the unbound 11O is still unknown).
the double helix is hydrogen bonded through the bases only so the bases are inside the helix only
as adenine combines with thymine and guanine with cytosine
phosphate are in the exterior of it
sugar groups constitute the double helix.
The physical properties of water is that it is clear, it has no taste. No odour. It freezes at 0 degrees Celsius and boils at 100 degrees Celsius. The different stages of water is liquid, solid and gas. It is liquid at normal state. Ice when solid and steam when it is a gas state.
It is essential for human life because majority of the human body is made out of water. The water in the body allows certain parts and organs to function properly. Without water humans are most like to become I’ll and even dehydrate causing major injuries. It is also essential for the brain to function