Химия для вступительных экзаменов на сестринские программы: лист заданий с ответами

What is a beta particle?

1. AA helium nucleus with two protons and two neutrons
2. BA wave of visible light
3. CA neutron that leaves the nucleus
4. DA high-energy electron released from a nucleus

What is activation energy?

1. AThe total energy released once the reaction has finished
2. BThe minimum energy reacting particles need for a reaction to happen
3. CThe energy needed to melt a solid
4. DThe energy stored in the products

What does the double arrow (⇌) in a chemical equation show?

1. AThe reaction is very fast
2. BThe reaction is reversible
3. CThe reaction releases heat
4. DThe reaction needs a catalyst

Which nuclear process powers the Sun?

1. AFission of uranium into smaller nuclei
2. BCombustion of hydrogen gas with oxygen in its core
3. CAlpha decay of helium
4. DFusion of hydrogen nuclei to form helium

When diluting a concentrated acid, which method is safe?

1. AAdd the acid slowly to the water
2. BAdd the water quickly to the acid
3. CMix them in any order, as long as it is fast
4. DAdd the water slowly to the acid

In a reaction at equilibrium, a product is continuously removed. What happens?

1. AThe reaction rate drops to zero
2. BThe reactants run out immediately
3. CMore product keeps forming as the equilibrium shifts to the right
4. DThe equilibrium shifts to the left to form more reactants

Which pair of substances could form a buffer solution?

1. AHydrochloric acid (HCl) and chloride (Cl⁻)
2. BCarbonic acid (H₂CO₃) and bicarbonate (HCO₃⁻)
3. CSodium chloride (NaCl) and water
4. DHydrochloric acid (HCl) and sodium hydroxide (NaOH)

How does soap help remove grease from skin?

1. AEach soap molecule has a polar end that attracts water and a nonpolar end that attracts grease
2. BSoap reacts with grease to form water and carbon dioxide
3. CSoap makes the grease more dense so it sinks
4. DSoap molecules are completely nonpolar, so they dissolve grease like a solvent