The smallest functional and structural unit of an organism, usually microscopic and consisting of cytoplasm and a nucleus in a membrane.
Answer: With atomic number 20, calcium atoms have 20 positive protons, and the ion has only 18 electrons, which means the net charge is +2. Calcium ions are essential for muscle contractions, nerve impulses, and bone maintenance.
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Answer/Explanation:
Wood: E
Freshly brewed black coffee: O
Water: O
Lucky Charms: E
Salt: O
Dirt: E
Sausage and mushroom pizza: E
Air: O
Milk: O
Gold: O
Any mixture that looks the same through the substance is homogenous. The different parts are unable to be visibly seen. (Any periodic element is homogenous)
Any mixture that can be easily determined a mix and cannot be evenly separated or dispersed is heterogenous.