While designing his recording studio, Brian was trying to determine what type of surface he should use for his studio walls. He wanted to be able to produce clear, crisp, sound. So he needed a surface that wouldn't cause his music to echo. What type of surface should Brian use for his studio walls?

Acoustic Foam.

Explanation:

Acoustic Foam: This is a kind of material, which is commonly known as it called a Studio Foam, it has a kind of wedge or pyramid shape that plays a big role in absorbing sound. Brian would have to use acoustic foam by placing them round the walls and ceiling as this would stop any echoing sound and in return give a crisp and clear sound when music is been played it the studio.

the leaf is an organ of a typical plant, and the main functions are to complete photosynthesis and allow the plant to exchange gas, just like how we have the respiratory system. leaves have the stomata, which collects maintains co2 and o2 levels. this is necessary for cell metabolism. the leaf also collects sunlight using chloroplasts. succinctly, leaves own a pivotal role in sustaining plant life.

periodic trends is an atom that gets larger as the number of electronic shells increase, the radius of atoms increases as you go down a certain group in the periodic table of elements. in general, the size of an atom will decrease as you move from left to right of a certain period.