Scheda di esercizi di Chimica per i test di ammissione a infermieristica con soluzioni

Quale tipo di legame tiene insieme il cloruro di sodio (sale da cucina)?

1. AIl legame a idrogeno
2. BIl legame metallico
3. CIl legame covalente
4. DIl legame ionico

Which of these is a chemical property?

1. ABoiling point
2. BFlammability
3. CColour
4. DDensity

Which method separates two liquids with different boiling points, such as alcohol and water?

1. ASieving
2. BFiltration
3. CDistillation
4. DUsing a magnet

How many oxygen atoms are in one formula unit of calcium nitrate, Ca(NO₃)₂?

1. A5
2. B2
3. C3
4. D6

Which coefficients balance __KClO₃ → __KCl + __O₂?

1. A2, 1, 3
2. B2, 2, 3
3. C1, 1, 3
4. D1, 1, 1

How does ionisation energy (the energy needed to remove an outer electron) generally change from left to right across a period?

1. AIt increases
2. BIt stays the same
3. CIt first falls, then rises sharply
4. DIt decreases

A solution of acetic acid conducts electricity only weakly, while hydrochloric acid of the same concentration conducts strongly. Why?

1. AHydrochloric acid contains metal atoms
2. BAcetic acid does not dissolve in water at all
3. CAcetic acid forms more ions than hydrochloric acid does
4. DAcetic acid only partly ionises, so it forms fewer ions

Why are the radioactive tracers used for medical imaging usually chosen to have short half-lives?

1. AThey stay active for many years, so a single dose can be used for every future scan
2. BThey emit only alpha particles, which are harmless inside the body
3. CThey give a strong signal for imaging but leave the body's tissues exposed only briefly
4. DShort half-life isotopes are not radioactive