Assertion (A) : γ-rays have very high penetrating power.
Reason (R) : γ-rays are high-energy electromagnetic radiations.
The waves from the high frequency end of the electromagnetic spectrum which do not have any mass are called the gamma rays. They have greatest power of penetration. They are the least ionizing but most penetrating and it is extremely difficult to stop them from entering the body. These rays carry huge amount of energy and can even travel through thin lead and thick concrete.
Therefore, we can see that statement 1 is correct and statement 2 is also correct.