The answer is B.
She can measure the mass of the water, marble and the graduated cylinder with the balance.
The volume of the water can be shown on the marked graduated cylinder, the volume of the marble can be measured by the volume difference of the water before and after the marble is put in.
Cations are positively charged ions. And for positive charged ions, it means the positive charges, protons, are more than the negative charges, the electrons.
Therefore Cations have fewer electrons than protons.
So the answer is: c. electrons; protons.
Answer:
F = 2.30 10⁴ N
Explanation:
The force required to link two gates must be equal to or greater than the electrostatic force of repulsion, because the protons have equal charges.
F = k q₁ q₂ / r²
Where k is the Coulomb constant that is worth 8.99 10⁹ N m² / C²
In this case the proton charge is 1.6 10⁻¹⁹ C and the distance between them is approximately the diameter of the core r = 10⁻¹⁵ m
Let's calculate
F = 8.99 10⁹ (1.6 10⁻¹⁹)² / (10⁻¹⁵)²
F = 2.30 10⁴ N
The bond strength must be equal to or greater than this value
Answer:
The time is 1.8s
Explanation:
The ball droped, will freely fall under gravity.
Hence we use free fall formula to calculate the time by the ball to hit the ground

Where h is the height from which the ball is droped, g is the acceleration due to gravity that acted on the ball, and t is the time taken by the ball to hit the ground.
From the question,
h=16m
Also, let take

By substitution we obtain,


Diving through by 9.8


square root both sides, we obtain


Answer:
z
Explanation:
x repersents a new moon and the others repersent quarter moons
(x is a new moon because new moons are often the phase when the moon is close to earths sun)