Užduočių lapas tema Chemija slaugos stojamiesiems egzaminams su atsakymais

What is an alpha particle made of?

1. APure electromagnetic energy
2. BA single high-energy electron
3. C2 protons and 2 neutrons
4. D1 proton and 1 electron

Apart from mercury, which element is a liquid at room temperature?

1. ASodium
2. BIodine
3. CChlorine
4. DBromine

Which unit is commonly used for the density of a liquid?

1. Ag·mL
2. Bg/mL
3. CmL/g
4. Dkg

A reaction has ΔH = −890 kJ/mol. What does the negative sign tell you?

1. AThe reaction is exothermic
2. BThe reaction is at equilibrium
3. CThe reaction is endothermic
4. DThe reaction needs a catalyst

What is the oxidation number of an element in its uncombined (elemental) form, such as Fe or O₂?

1. A0
2. BIt equals the group number
3. C+1
4. D−1

A piece of metal has a density of 8 g/cm³ and a volume of 5 cm³. What is its mass?

1. A1,6 g
2. B40 g
3. C0,625 g
4. D13 g

How many atoms in total are in 0,5 mol of water, H₂O?

1. A6,02 × 10²³
2. B3,01 × 10²³
3. C1,81 × 10²⁴
4. D9,03 × 10²³

Kodėl aliejus netirpsta vandenyje?

1. AAliejus reaguoja su vandeniu ir sudaro kietą medžiagą
2. BAliejus nepoliarinis, o vanduo poliarinis, ir „panašus tirpsta panašiame"
3. CAliejaus molekulės yra įkrauti jonai
4. DVanduo per tankus, kad su kuo nors susimaišytų