Chemia na egzaminy wstępne na pielęgniarstwo: karta pracy z odpowiedziami

Jaki rodzaj wiązania powstaje, gdy atomy uwspólniają elektrony?

1. AWiązanie jonowe
2. BWiązanie kowalencyjne
3. CWiązanie metaliczne
4. DWiązanie jądrowe

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

1. ASieving
2. BDistillation
3. CFiltration
4. DUsing a magnet

What does the rule "like dissolves like" mean?

1. ASolids dissolve only in other solids
2. BOnly substances with identical formulas can ever dissolve in each other
3. CEvery substance dissolves in water
4. DPolar solvents dissolve polar substances, and nonpolar solvents dissolve nonpolar ones

A radioactive isotope has a half-life of 5 days. A sample starts with 80 g. How much is left after 10 days?

1. A0 g
2. B10 g
3. C40 g
4. D20 g

In the balanced equation __Mg + __HCl → __MgCl₂ + __H₂, what is the coefficient of HCl?

1. A4
2. B1
3. C2
4. D3

Why does ice float on liquid water?

1. AIce has a higher mass than the same volume of water
2. BIce is denser than liquid water
3. CIce contains trapped air from the freezer
4. DIce is less dense than liquid water

In the reaction NH₃ + H₂O ⇌ NH₄⁺ + OH⁻, which substance acts as the Brønsted–Lowry acid?

1. ANH₄⁺ only
2. BOH⁻
3. CH₂O
4. DNH₃

Burning a match is strongly exothermic, so why does it not catch fire until it is struck?

1. AStriking supplies the activation energy to start the reaction
2. BStriking pushes extra oxygen into the chemicals of the match head
3. CThe match must first absorb all its energy from the air
4. DStriking makes the reaction endothermic