Answer:
Alkali metals are soft and have low melting points.
A medium can be anything that a wave can pass through e.g the medium can be solid objects, air, water, etc.
Answer: Either A or D
Geologists and paleontologists constructed the geologic table based on the relative positions of different strata and fossils, and estimated the time scales based on studying rates of various kinds of weathering, erosion, sedimentation, and lithification.
Every organic molecules/compound contains carbon (c).
Some other very abundant are hydrogen, nitrogen, oxygen, phosphorus, and sulfur.
I learned this with the acronym CHNOPS.
C - Carbon
H - Hydrogen
N - Nitrogen
O - Oxygen
P - Phosphorus
S - Sulfur
Hope this helps!
