Chemistry for nursing entrance exams worksheet with answers

Which of these is a physical change?

1. ABread being toasted until brown
2. BWater boiling into steam
3. CMilk turning sour
4. DIron rusting

Which positive ion is found in the highest concentration inside most body cells?

1. ACalcium (Ca²⁺)
2. BMagnesium (Mg²⁺)
3. CSodium (Na⁺)
4. DPotassium (K⁺)

Chlorine, bromine and iodine are examples of which group?

1. AAlkali metals
2. BNoble gases
3. CHalogens
4. DTransition metals

Why does ice float on liquid water?

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

The amino acid glycine has an –NH₂ group and a –COOH group. What are these two groups called?

1. AA carbonyl group and an ester group
2. BA phosphate group and a hydroxyl group
3. CAn amino group and a carboxyl group
4. DA hydroxyl group and a methyl group

Why is a water molecule polar?

1. AWater molecules are straight, with both hydrogens on one line
2. BWater has ionic bonds between hydrogen and oxygen
3. CHydrogen is more electronegative than oxygen
4. DOxygen pulls the shared electrons more strongly, and the molecule is bent

Why is Dmitri Mendeleev's early periodic table regarded as such a success?

1. AHe arranged the elements by atomic number, which he had discovered
2. BHe proved that the atoms of every element contain electrons
3. CHe left gaps and correctly predicted the properties of elements not yet discovered
4. DHe discovered the noble gases and placed them in group 18

Why does atomic radius decrease from left to right across a period?

1. AMore protons pull the electrons of the same outer shell closer
2. BThe atoms lose electrons across the period
3. CEach element adds a new electron shell
4. DNeutrons push the electrons outward less strongly