Answer:
A. Cell
Explanation:
Cells are basic units of structure and function in living things. This means that cells form the parts or an organism and carry out all of the an organism's processes, or functions.
Answer:
D. In both, vibrations occur in a parallel direction to the direction of the wave.
Explanation:
It is not true that in both mechanical and electromagnetic waves, vibrations occur in parallel direction to the direction of the wave.
As with all waves, they are disturbances that transfers energy without moving the materials of the medium.
- Electromagnetic waves have only one way of propagation which is a vibration in both parallel and longitudinal direction.
- Mechanical waves can be propagated either in a parallel direction or longitudinal direction and not both.
Answer:
- <em>The net charge of the ionic compound calcium fluoride is </em><u><em>zero (0).</em></u>
<em>Explanation:</em>
<em>Ionic compounds,</em> such as covalent ones, have zero net charge; this is, they are neutral.
Substances with net positive charge are cations and substances with net negative charge are anions.
The charges in the <em>ionic compound calcium flouride</em> are distributed in this way:
- Calcium charge: Ca²⁺: this is, each calcium ion has a 2 positive charge
- Fluoride charge: F⁻: each fluoride ion has a 1 negative charge.
- Then, the <em>net charge</em> is: 1 × (2+) + 2 × (1-) = +2 - 2 = 0.
So, a two positve charge, from one calcium ion, is equal to two negative charges, from two fluoride tions, yielding a <u>zero net charge</u>.
