Chemistry:

How many characteristic properties must be alike for two substances to be the same?

Ms. Block's students are studying chemical reactions. A classic reaction occurs when a metal is added to hydrochloric acid.

What subatomic particle creates electric power, and how does it do it?

Patients with prostheses needing repair or replacement usually require surgery. However, one type of prosthesis needs no external power source, which addresses this challenge. This type of prosthesis is called what? O a. A passive prosthesis O b.

Which statement best describes how a new human trait develops and can be passed on to future generations? A) A mutation in a stomach cell results in the inability of a woman to produce a certain digestive enzyme.

What are some ideas for a compound machine for my middle school invention science project that can be useful in people's daily lives? I need a explanation of why it's important.

Which statement about the Nobel gases is most reliable

Which of the following groups contains members with similar chemical reactivity? A) SC, Y, Zr B) Li, Be, C C) C, N, O D) Be, Mg, Sr

What structure holds the sister chromatids to the spindle fibers? a. kinetochore b. chromatin c. mpf d. cyclin e. centromere

What is the concentration of OH - in pure water at 298k

Consider the elements of group 4a (the "carbon family") : c, si, ge, sn, and pb. what is the trend in metallic character as one goes down this group?