A particle in an iron atom has a negative charge and moves in the space around the nucleus. Which particle is described?

A particle in a calcium atom has a positive charge, sits in the dense center of the atom, and contributes to atomic mass. Which particle is described?

A particle in an oxygen atom sits in the nucleus, adds to the atom's mass, and has no electric charge. Which particle is described?

Changing the number of which particle would change a carbon atom into a different element?

In a chloride ion, the extra particle that gives the ion its negative charge is found outside the nucleus. Which particle is it?

During a long workout, sweat carries away the main positive ion in extracellular fluid, often replaced in sports drinks first. Which ion is that?

A nerve impulse depends on an ion rushing into the neuron through voltage-gated channels during depolarization. Which ion enters first?

After a neuron fires, an ion moves out of the cell to help repolarize the membrane. Which ion mainly leaves?

A skeletal muscle fiber cannot contract normally when the ion released from the sarcoplasmic reticulum is unavailable. Which ion is required?

A lab report shows low blood levels of the main negative ion of extracellular fluid, which helps balance fluid movement with sodium. Which ion is low?

Blood resists a dangerous drop in pH because carbonic acid can be converted into a charged base that accepts hydrogen ions. Which ion is part of this buffer system?

Table salt separates in body fluid into oppositely charged particles that attract each other when dry. Which bond holds the dry crystal together?

In a water molecule, oxygen and hydrogen share electrons rather than becoming separate charged particles. Which bond joins those atoms?

Two water molecules are held near each other because the slightly positive end of one attracts the slightly negative end of another. Which attraction is this?

A protein keeps its folded shape partly because weak attractions form between polar parts of nearby chains. Which attraction is most likely involved?

An enzyme's active site depends on atoms sharing electrons in its amino acid backbone. Which bond forms that backbone?

A gastric sample has a pH of 2.0. Which description fits that fluid?

Arterial blood reads pH 7.40 on a lab report. Which description best fits that value?

Pure water in a lab beaker reads pH 7.0 at room temperature. Which description fits that value?

A patient's blood pH is 7.28. Compared with normal arterial blood, which acid-base description fits this value?

A pancreatic juice sample reads pH 8.2 as it enters the small intestine. Which description fits that fluid?

A runner's core temperature changes only slightly even while working muscles release heat. Which property of body water helps stabilize temperature?

Plasma can carry glucose, salts, and many small polar molecules through vessels. Which property of water makes this transport possible?

A sweat droplet absorbs heat from skin and then leaves the body as vapor. Which property of water makes cooling by sweating effective?

Water molecules cling to one another as a thin film lines the inner surface of small airways. Which property explains this attraction between water molecules?