Answer:
Rate at which current flows is measured in amperes
Explanation:
The rate of flow of electrons constitutes the current. The electrons flow from lower electric potential to higher electric potential. When there is no potential difference then no electron will flow. The direction of the current and the electron are in opposite direction.
The direction of electron from the negative terminal to the positive terminal. The direction of current is from the positive terminal to the negative terminal.The current is measured in ampere.
The expression for current and the charge is as;
Here, q is the charge, t is the time taken and I is the current.
According to the given problem, Jodi made a list about electric current to help her study for a test. He described that electrons move from areas of low to high electric potential, voltage causes current to flow and movement of electrons is continuous in a current.
But he did error. It should be "rate at which charges flow" instead of rate at which current flow.
Therefore, the option (4) is correct.
1. I think is letter b.
2. I thinks it's letter c.
Answer:
The part that completes the nuclear equation is:

Explanation:
<h2>A) Preliminar explanation</h2>
The <em>nuclear equation</em> represents a nuclear reaction: the change of the nucleus of an atom.
The given equation represents an actinium atom releasing an alpha particle.
This is the meaning of each part of the equation:
- Ac is the chemical symbol of actinium
- The superscript to the left of the chemical symbol is the mass number of the atom (number of protons plus number of neutrons). The mass number is 225.
- The subscript to the left of the chemical symbol is the atomic number of the atom (number of protons). The atomic number is 89.
is the symbol of the alpha particle. It is an atom of helium- The mass number is 4
- The atomic number is 2
<h2>B) Solution</h2>
To <em>complete the nuclear equation </em>you must do two balances: mass number balance and atomic number balance.
<u>i) Mass number balance</u>
- 225 = A + 4 ⇒ A = 225 - 4 = 221
<u>ii) Atomic number balance</u>
- 89 = Z + 2 ⇒ Z = 89 - 2 = 87
Therefore, the mass number of the unknown atom is 221, and the atomic number is 87.
From a periodic table, the element with atomic number 87 is francium, Fr.
Now, you have the chemical symbol, the atomic number, and the mass number of the unknown atom, which lets you to write the atom that completes the <em>nuclear equation</em>.

A wave that is traveling fast can be said to have a high speed.<em> (b) </em>
Just like a car, motorcycle, or freight train that is traveling fast.