Homework Week 10: Atoms and Elements

Which subatomic particles are located in the nucleus of an atom? Choose ALL that apply.

• Electrons

• Neutrons

• Protons

• Isotopes

Answer explanation

The nucleus of an atom contains protons and neutrons. Protons are positively charged, while neutrons have no charge. Electrons are found in the electron cloud surrounding the nucleus, and isotopes refer to variants of elements, not particles.

Which of the following best describes the modern model of atomic structure? Select ALL that apply.

• Electrons orbit the nucleus in fixed paths

• Electrons are in a cloud around an atom

• Electrons and protons are the same in size

• The atom is mostly empty space

Answer explanation

The modern atomic model describes electrons as existing in a cloud around the nucleus, indicating their probabilistic locations. Additionally, most of the atom's volume is empty space, with a small, dense nucleus at the center.

What does the atomic number of an element represent on the periodic table?

• The number of protons in the nucleus

• The number of electrons in the outer shell

• The total number of protons and neutrons

• The number of electrons in the atom

Answer explanation

The atomic number of an element represents the number of protons in its nucleus. This defines the element's identity and its position on the periodic table, making it the correct choice.

Which of the following choices puts the numbers in the picture in order from 1-3?

• electrons, protons, neutrons

• protons, electrons, neutrons

• neutrons, electrons, protons

Answer explanation

The correct order from 1-3 is electrons, protons, neutrons. Electrons are the lightest and are typically listed first, followed by protons, and then neutrons, which are heavier than both.

Tags

NGSS.MS-PS1-1

When two or more atoms interact to form new substances, which forces hold them together?

• Magnetic forces

• Electrical forces

• Gravitational forces

• Mechanical forces

Answer explanation

When atoms interact to form new substances, they are held together by electrical forces, specifically the attraction between positively charged nuclei and negatively charged electrons, which create chemical bonds.

Tags

NGSS.MS-PS1-1

Select ALL the true statements about the items in the picture.

• Side A represents one atom

• Side B represents an element

• Side A focuses on the subatomic particles: electrons, protons, neutrons

• Side B focuses on two or more atoms of the same type "bonded" together to create an element

Answer explanation

Side A represents one atom, focusing on subatomic particles like electrons, protons, and neutrons. Side B represents an element, which consists of two or more atoms of the same type bonded together.

Tags

NGSS.MS-PS1-1

What are the 3 particles that make-up the atom?

• protons, neutrons, and isotopes

• neutrons, isotopes, and electrons

• positives, negatives, and electrons

• protons, neutrons, and electrons

Answer explanation

The correct answer is protons, neutrons, and electrons, as these are the three fundamental particles that make up an atom. Isotopes are variations of elements, not fundamental particles.

Tags

NGSS.MS-PS1-1

Which is an electron?

• A

• B

• C

Answer explanation

Choice A is the correct answer as it represents an electron, which is a subatomic particle with a negative charge. Options B and C do not correspond to the definition of an electron.

Tags

NGSS.MS-PS1-1

Which letter represents a proton?

• A

• B

• C

• D

Answer explanation

The letter B represents a proton, which is a positively charged particle found in the nucleus of an atom. This choice is correct as protons are fundamental components of atomic structure.

Tags

NGSS.MS-PS1-1

Which letter represents a neutron?

• A

• B

• C

• D

Answer explanation

The letter A represents a neutron, which is a subatomic particle found in the nucleus of an atom. Neutrons have no electric charge, distinguishing them from protons and electrons.

Tags

NGSS.MS-PS1-1