\[ **BT: [[home]]** ] --- # matter and energy ## matter Matter is any substance that has mass and take space by having volume.[^1] All everyday objects we can touch are made up of [[#atoms]].[^2] Most matter—at least, of the matter we experience in our daily lives—is **baryonic matter**. In contrast, **non-baryonic matter** includes [[neutrinos]], [[free electrons]], and [[cosmos#dark matter|dark matter]].[^3] ### atoms [[An atom is the smallest unit of any element; atoms themselves are made up of subatomic particles (e.g. protons, electrons, neutrons).]][^4] [[Higher levels of organisation are built from lower levels (i.e. molecules combine to form cells, cells combine to form tissues, tissues combine to form organs, etc).]][^5] [[Two or more atoms combine to form a molecule, e.g. water molecules, proteins, sugars. Thus, molecules are the building blocks of all living things.]][^6] ### elements [[All matter in the universe is composed of one or more unique pure substances called elements.]][^7] ### chemical compounds - see: - [[citric acid]] [^1]: ‘Matter’, Wikipedia, last edited 4 May 2026, 14:30 (UTC), https://en.wikipedia.org/wiki/Matter. [^2]: ‘Matter’, Wikipedia, last edited 4 May 2026, 14:30 (UTC), https://en.wikipedia.org/wiki/Matter. [^3]: ‘Matter’, Wikipedia (Simple English), last edited 16 April 2026, 21:56 (UTC), https://simple.wikipedia.org/wiki/Matter. [^4]: Lindsay M. Biga et al., *[[Biga, Anatomy and Physiology, 2019|Anatomy & Physiology]]* (Oregon State University, 2019), part 1.2., <https://open.oregonstate.education/aandp/chapter/1-2-structural-organization-of-the-human-body/>. [^5]: Lindsay M. Biga et al., *[[Biga, Anatomy and Physiology, 2019|Anatomy & Physiology]]* (Oregon State University, 2019), part 1.2., <https://open.oregonstate.education/aandp/chapter/1-2-structural-organization-of-the-human-body/>. [^6]: Lindsay M. Biga et al., *[[Biga, Anatomy and Physiology, 2019|Anatomy & Physiology]]* (Oregon State University, 2019), chap. 1.2, <https://open.oregonstate.education/aandp/chapter/1-2-structural-organization-of-the-human-body/>. [^7]: Lindsay M. Biga et al., *[[Biga, Anatomy and Physiology, 2019|Anatomy & Physiology]]* (Oregon State University, 2019), part 1.2, <https://open.oregonstate.education/aandp/chapter/1-2-structural-organization-of-the-human-body/>.