When we say a wave requires a medium, what do we mean?

Mechanical waves are waves that require a medium. This means that they have to have some sort of matter to travel through. These waves travel when molecules in the medium collide with each other passing on energy.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

honesty and integrity.

inspire others.

commitment and passion.

good communicator.

decision-making capabilities.

accountability.

delegation and empowerment.

creativity and innovation.

here are the traits of a good leader.i'm not going to give you the examples so you can copy right it.that's illegal but i hope that this you out.