ALL sound waves are longitudinal, I know this of of many ways, I study astronomy and the sound waves of blackholes as they form. award me brainliest and I award you with a correct answer :)
Answer:
I think carbon and hydrogen
The atomic number is the total number of protons in the nucleus. The mass number is the total number of particles in the nucleus. That includes the neutrons and the protons. So, the atomic number is 31. When you look at the element on the periodic table with a designated atomic number of 31, that would be Gallium, with a symbol of Ga. Mass number is 31 + 36 = 67. So, the answer is A.
D. the reflection of each concave lens makes the object appear larger
