All categories

4 years ago

Many people believe that the atomic number of the atom is the number of electrons in the atom. Describe when this is the case

2 answers:

5 0

When the atom is neutral and the number of electrons and the number of protons are equal.

lesya [120]4 years ago

4 0

Answer: The atomic number of the atom is the number of electrons in the atom only when the atom is neutral.

Explanation: For a neutral atom, the number of positive charges is equal to the number of negative charges and thus the atomic number is equal to the number of electrons or the number of protons.

But for a positive and a negative ion, the electrons are lost and gained respectively by that element and thus the number of electrons are not equal to the number of protons. Now atomic number is equal to the number of protons only. The number of electrons = number of protons - charge.

Example: For sodium $Na$ , the atomic number is 11 and it has 11 electrons.

For sodium ion $Na^+$ , the atomic number is 11 but the number of electrons = (11-1) = 10.

You might be interested in

A box of Thanksgiving presents slides across a waxy floor at 20m/s. It comes to a stop in 4 seconds. What distance did the box t

mars1129 [50]

Answer:

V = d/t = 20

20=d/4 so d = 80

6 0

3 years ago

A person is pulling their 20 kg luggage using the luggage handle. The handle is at an angle of 56 degrees above the horizontal.

rusak2 [61]

Answer:

The answer to your question is: a = 1.99 m/s²

Explanation:

Data

mass = 20 kg

angle = 56°

Force = 71 N

horizontal acceleration = ?

Process

Find the horizontal force

cos Ф = adjacent side / hypotenuse

adjacent side = hypotenuse x cosФ

adjacent side = 71 x cos 56

a.s. = 39.70 N

Newton's second law

F = ma

a = F/m

a = 39.7 / 20

a = 1.99 m/s²

4 0

4 years ago

Be sure you understand why a pendulum in equilibrium hanging in a car that is accelerating forward tilts backward, and then cons

Gnesinka [82]

Answer:

A helium filled balloon floats forwards in a accelerating car because of the pressure difference between the front and the back of the car. When the car is accelerating, the air moves relitive to the car and the consequence is that the pressure in the back is slightly higher than in the front; which results in net force in forward direction.

hit that heart please leave brainliest and let me know if want me to answer or explain it in a different way :)

6 0

3 years ago

Calculate the momentum of a 1200kg car with a velocity of 25m/s

timurjin [86]

Momentum = mass x velocity
= (1200)(25)
Momentum = 30,000 kg m/sec

hope this helps :)

4 0

3 years ago

Read 2 more answers

Consider a simple tension member that carries an axial load of P=22.44N. Find the total elongation in the member due to the load

rodikova [14]

Answer:

The total elongation for the tension member is of 0.25mm

Explanation:

Assuming that material is under a linear deformation then the relation between the stress and the specific elongation is given as:

$\sigma=E*\epsilon$ (1)

Where E is the modulus of elasticity, σ the stress and ε the specific deformation. Also, the total longitudinal elongation can be expressed as:

$\delta L=L*\epsilon$ (2)

Here L is the member extension and δL the change total longitudinal elongation.

Now if the stress is found then the deformation can be calculated by solving the stress-deformation equation (1). The stress applied sigama is computed dividing the axial load P by the cross-sectional area A:

$\sigma=P/A$