Live practice

Metals generally lose electrons, conduct heat and electricity, are lustrous and malleable, and form basic or amphoteric oxides. Non-metals tend to gain/share electrons, conduct poorly, are brittle as solids, and commonly form acidic or neutral oxides.

Neutrality makes protons equal to electrons. Z=29 is copper, whose stable ground configuration has a filled 3d subshell.

Gas volumes at the same temperature and pressure follow the coefficients in the balanced equation.

Choose each group independently.

1. \(A\cap B=\{7,9,11\}\).
2. \(B\cap C=\{11,13\}\).
3. \(A\cap C\cap D=\varnothing\).
4. \(A\cap C=\{11\}\).
5. \(B\cap D=\varnothing\).
6. \(A\cap(B\cup C)=\{7,9,11\}\).
7. \(A\cap D=\varnothing\).
8. \(A\cap(B\cup D)=\{7,9,11\}\).
9. \((A\cap B)\cap(B\cup C)=\{7,9,11\}\).
10. \((A\cup D)\cap(B\cup C)=\{7,9,11,15\}\).

Resistance \[\begin{aligned}R &= 220^\frac{2}{100}\\&= 484\end{aligned}\] Ω. At 110 V, \[\begin{aligned}P &= 110^\frac{2}{484}\\&= 25\end{aligned}\] W.

\(u=-10\) cm, \(f=+15\) cm. Mirror formula:

Positive v means behind the mirror. \[\begin{aligned}m &= -\frac{v}{u}\\&= +0.600\end{aligned}\], so the image is virtual, erect and diminished.

In a sensitive plant, touch generates signals that cause motor cells to lose water and turgor; the leaf folds without muscle or growth. In a leg, motor neurons deliver electrical impulses to muscle fibres, where contractile proteins use ATP to shorten and pull bones across joints. Plant movement is turgor-driven; leg movement is muscular and coordinated by the nervous system.

Most fat digestion occurs in the small intestine. Bile from the liver neutralises acidic chyme and emulsifies large fat globules into small droplets, increasing surface area. Pancreatic and intestinal lipases then hydrolyse fats into fatty acids and glycerol. These products enter villus cells and are mainly absorbed into lacteals.