This video segment adapted from A Science Odyssey takes a look at the scale of the atom and the tremendous amount of space between the electrons and the nucleus. If all this empty space exists in matter, how can any substance be solid?

Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

By the end of this section, you will be able to:Describe the structure of eukaryotic cellsCompare animal cells with plant cellsState the role of the plasma membraneSummarize the functions of the major cell organelles

By the end of this section, you will be able to:Describe the cytoskeletonCompare the roles of microfilaments, intermediate filaments, and microtubulesCompare and contrast cilia and flagellaSummarize the differences among the components of prokaryotic cells, animal cells, and plant cells

By the end of this section, you will be able to:Define matter and elementsDescribe the interrelationship between protons, neutrons, and electronsCompare the ways in which electrons can be donated or shared between atomsExplain the ways in which naturally occurring elements combine to create molecules, cells, tissues, organ systems, and organisms

By the end of this section, you will be able to:Define matter and elementsDescribe the interrelationship between protons, neutrons, and electronsCompare the ways in which electrons can be donated or shared between atomsExplain the ways in which naturally occurring elements combine to create molecules, cells, tissues, organ systems, and organisms

Working in teams of three, students perform quantitative observational experiments on the motion of LEGO MINDSTORMS(TM) NXT robotic vehicles powered by the stored potential energy of rubber bands. They experiment with different vehicle modifications (such as wheel type, payload, rubber band type and lubrication) and monitor the effects on vehicle performance. The main point of the activity, however, is for students to understand that through the manipulation of mechanics, a rubber band can be used in a rather non-traditional configuration to power a vehicle. In addition, this activity reinforces the idea that elastic energy can be stored as potential energy.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Critical defects that compromise the nucleus during cell division could be the basis for the age-accelerating effects of people living with progeria. Hutchinson-Gilford progeria syndrome is a genetic disorder that causes premature aging. Affecting one in 8 million newborns worldwide, the disorder is extremely rare—and fatal. The rapid aging of the cardiovascular system causes death due to heart attack or stroke in patients by their mid-teens. Progeria is caused by a tiny point mutation in the lamin A gene. This gene is responsible for producing structural proteins called lamins, which form the scaffolding that holds the cell nucleus together. The mutated form of prelamin A called progerin destabilizes the cell nucleus—the genetic control center of cells. The result is the fast-aging effects observed in progeria. But the link from gene mutation to physical disorder has remained a mystery. Previous studies have looked only at models of progeria, not at actual patient cells..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

Students learn about the periodic table and how pervasive the elements are in our daily lives. After reviewing the table organization and facts about the first 20 elements, they play an element identification game. They also learn that engineers incorporate these elements into the design of new products and processes. Acting as computer and animation engineers, students creatively express their new knowledge by creating a superhero character based on of the elements they now know so well. They will then pair with another superhero and create a dynamic duo out of the two elements, which will represent a molecule.

Are all atoms of an element the same? How can you tell one isotope from another? Use the sim to learn about isotopes and how abundance relates to the average atomic mass of an element.

Are all atoms of an element the same? How can you tell one isotope from another? Use the sim to learn about isotopes and how abundance relates to the average atomic mass of an element.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"St. Louis University researchers have discovered some of the molecular processes that lead to decline in patients with progeria. Their work also helps explain why certain drugs seemingly rejuvenate progeria cells, which could hint at more potent therapies against progeria. Hutchinson–Gilford progeria syndrome is a rare genetic disease that causes premature aging. Rapid aging of different tissues causes death by teenage years, normally due to cardiovascular complications. Currently, therapies for this devastating disease provide patients minimal benefit. The origin of progeria is a mutation in the lamin A gene—responsible for fabricating structural proteins that help keep the cell nucleus sturdy and the genome intact. The mutated lamin A protein “progerin” destabilizes the cell nucleus, causes DNA damage, and ultimately leads to the aging effects found in patients with progeria. Now, the researchers have delved deeper to understand how progerin wreaks damage at the molecular level..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Control energy production in a nuclear reactor! (Previously part of the Nuclear Physics simulation - now there are separate Alpha Decay and Nuclear Fission sims.)

Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Control energy production in a nuclear reactor! (Previously part of the Nuclear Physics simulation - now there are separate Alpha Decay and Nuclear Fission sims.)

Ancient alchemists attempted but failed to turn different substances into gold. It turns out that the only way to turn one element into another element is using nuclear chemistry! Nuclear reactions change the composition of an atom's nucleus, and this process is useful for many applications.