Water Structure and Polarity
These are the two elements that chemically make up a molecule of water (H₂O).
What are hydrogen and oxygen?
This type of attractive force occurs between molecules of the same kind, such as water attracting water.
What is cohesion?
Unlike most solids which sink in their liquid state, solid water (ice) does this when placed in liquid water.
What is float?
Water is often referred to by this nickname because of its incredible ability to dissolve a vast array of substances.
What is the Universal Solvent?
Pure water sits right in the middle of the pH scale with this exact pH value.
What is 7 (or neutral)?
Because oxygen pulls shared electrons closer to itself than hydrogen does, a water molecule exhibits this type of bond within the molecule.
What is a covalent bond?
This property allows water molecules to stick to different, unlike substances or surfaces.
What is adhesion?
Human bodies use this evaporative process to absorb body heat and cool down during exercise.
What is sweating?
This term literally means "water loving" and describes polar or ionic substances that easily dissolve in water.
What is hydrophilic?
Substances with a pH lower than 7, such as lemon juice, vinegar, and stomach acid, are classified as this.
What are acids?
This term describes a molecule that has an uneven distribution of charge, resulting in partially positive and partially negative poles.
What is a polar molecule?
Caused by cohesive forces acting as an invisible "skin," this phenomenon allows small items like paperclips or basilisk lizards to stay on top of liquid water.
What is surface tension?
This ecological benefit occurs in freezing weather when floating ice forms a top layer on lakes and ponds, protecting organisms underneath.
What is insulating the deeper water to keep aquatic life alive?
This term literally means "water fearing" and describes non-polar substances like oil or fats that do not mix with water.
What is hydrophobic?
Substances with a pH greater than 7, such as bleach and ammonia, are known by either of these two terms.
What are bases (or alkaline)?
Due to electron repulsion among its unshared electron pairs, a water molecule forms this specific geometric shape.
What is a bent V-shape?
This process enables water to travel upward through narrow spaces against the force of gravity, such as moving up celery stalks or plant stems.
What is capillary action?
Water requires a high amount of heat to change temperature by 1°C per gram (1 cal/g/°C), a term known by this scientific property.
What is high specific heat?
When table salt (NaCl) dissolves in water, it breaks into these two charged particles.
What are sodium ions (Na+) and chloride ions (Cl-)?
According to the chemical equation H₂O ⇌ H⁺ + OH⁻, acids increase the concentration of H⁺ ions, while bases increase the concentration of this ion.
What is hydroxide (OH⁻)?
In a water molecule, these specific partial charges (represented by delta symbols) are assigned to the oxygen atom and the hydrogen atoms, respectively.
What are a slightly negative charge (δ-) for oxygen and a slightly positive charge (δ+) for hydrogen?
When conducting a penny droplet test, water forms a higher dome than 40% alcohol because water possesses stronger inter-molecular forces of this type.
What are hydrogen bonds (or stronger cohesive forces/surface tension)?
On a molecular level, ice is less dense than liquid water because its hydrogen bonds stabilize into a structure that does this to the molecules.
What is spacing the water molecules farther apart?
When salt dissolves, water's partially negative oxygen atoms surround this specific positive ion.
What is the sodium ion (Na+)?
Human blood must maintain a strictly regulated, slightly alkaline pH range within these two decimal values.
What is 7.35 to 7.45?