Số amin bậc một có cùng công thức phân tử C3H9N là

A. 3. B. 1. C. 2. D. 4

What elements have 2 electrons inthe 4s sublevel

Which statement correctly identifies the scientific question and describes why the question is scientific? question 1 refers to the supernatural.question 2 reflects a moral or social value.question 3 refers to something that can be measured.question 4 reflects a question that can’t be observed.

At stp, which substance is the best conductor of electricity? a. nitrogen b. neon c. sulfur d. silver