RC

Which statement correctly describes the location and charge of the electrons in an atom?

• The electrons are inside the nucleus and have no charge.

• The electrons are outside the nucleus and have no charge

• The electrons are inside the nucleus and have a negative charge.

• The electrons are outside the nucleus and have a negative charge.

Answer explanation

The electrons are found in the energy levels of the electron cloud surrounding the nucleus.

What is the atomic mass number?

• the number of protons in the nucleus

• the number of protons and neutrons in the nucleus

• the number of neutrons in the nucleus

• the number of protons and electrons in the atom

Which of these best describes one of the subatomic particles that could be found at location X in the model of an atom shown in the illustration.

• It has mass but no charge

• It has no mass and a positive charge

• It has a large mass and a negative charge

• It has no mass and an equal number of positive and negative charges

Answer explanation

The nucleus of the atom contains protons (positive charges) and neutrons (neutral/no charges).

Tags

NGSS.MS-PS1-1

A model of a beryllium atom is shown in the illustration. What type of particles are found in the cloud surroounding the atom's nucleus?

• Positively charged particles and negatively charged particles

• Negatively charged particles only

• Neutral particles and postiviely charged particles

• Positively charged particles only

Answer explanation

The electron cloud, containing negatively charged electrons, surrounds the nucleus of the atom

Tags

NGSS.MS-PS1-1

Which letter represents amplitude? (a)  

• A

• B

• C

• D

• E

Tags

NGSS.MS-PS4-1

List the steps of the scientific method

d

e

f

c

b

a

Analyze results

Draw conclusions

Conduct experiment

Form a hypothesis

Communicate results

Ask a question

Tags

NGSS.MS-LS1-5

How many protons, neutrons, and electrons are present in an atom of Hafnium (Hf) with a mass number of 178?

• 72 protons, 178 neutrons, 106 electrons

• 72 protons, 106 neutrons, 72 electrons

• 178 protons, 250 neutrons, 72 electrons

• 106 protons, 72 neutrons, 106 electrons

Answer explanation

The atomic number equals the number of protons in the nucles of the atom. The number of electrons equals the number of protons.

Tags

NGSS.MS-PS1-1

The table lists three characteristics of an atom of an element. An atom of which element is described by the data in the table?

• Radon (Rn)

• Cadmium (Cd)

• Rubidium (Rb)

• Astatine (At)

Answer explanation

The number of protons determines the identity of the atom. Atomic number equals the number of protons.

Tags

NGSS.MS-PS1-1

Tin (Sn) is a soft white metal. It has a low melting point compared to other metals.Tin is widely used as a coating for cans of food. Which statement correctly describes the atoms of tin.

• Tin atoms have 50 protons

• Tin atoms have 5 valence electrons

• Tin atoms have 119 neutrons

• Tin atoms have 68 electrons

Answer explanation

The number of protons determines the identity of the atom. The atomic number equals the number of protons

Tags

NGSS.MS-PS1-1

What is the atomic number of this atom?

• 7

• 14

• 21

• none of the above

Tags

NGSS.MS-PS1-1