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

At sea level, at what temperature does pure water freeze?

1. A32 °C (90 °F)
2. B0 °C (32 °F)
3. C−32 °C (−26 °F)
4. D100 °C (212 °F)

In a chemical equation, what does the symbol (aq) after a formula mean?

1. AA gas
2. BDissolved in water
3. CA pure liquid
4. DA solid

According to collision theory, what must happen for particles to react?

1. AThey must have the same mass
2. BThey must both be in the solid state at the same time
3. CThey must stay completely still next to each other
4. DThey must collide with enough energy and the right orientation

What is nuclear fission?

1. AThe loss of electrons from an atom
2. BThe joining of two light nuclei to form a heavier nucleus
3. CThe burning of uranium in oxygen
4. DThe splitting of a heavy nucleus into smaller nuclei

Which element has chemical properties most similar to calcium?

1. APotassium
2. BCarbon
3. CScandium
4. DMagnesium

Why does the vapour pressure of a liquid increase as it is heated?

1. AThe molecules become heavier and press harder on the surface
2. BMore molecules have enough energy to escape into the gas phase
3. CThe liquid's volume decreases and squeezes out vapour
4. DThe attractions between the molecules become stronger

Why does a sodium ion (Na⁺) have almost the same mass as a sodium atom?

1. AThe ion has one fewer proton, which has a tiny mass
2. BThe ion gains a neutron that balances the loss
3. CIons and atoms always have exactly the same mass
4. DThe only difference is one electron, which has a tiny mass

At room temperature chlorine (Cl₂) is a gas, bromine (Br₂) is a liquid and iodine (I₂) is a solid. What best explains this trend?

1. AIodine forms hydrogen bonds but chlorine does not
2. BLarger molecules with more electrons have stronger dispersion forces
3. CThe covalent bond in I₂ is much stronger than in Cl₂
4. DChlorine is ionic, while iodine is metallic