BMAT 2008-S2

Which one of the following involves active transport?

Element Y forms an ion Y ^3- with the electronic configuration 2, 8, 8.

A radioactive isotope X decays into the stable isotope Y with a half-life of 20s.

In the formula P = 2r²t

r = 3 x 10^-³                       t = 2.5 x 10^⁴

In mice the recessive form of a gene causes the death of the fetus if present in the homozygous state. Mice heterozygous for this gene were crossbred.

Look at the equation for making chlorine gas and decide which answer will provide you with the numbers to balance it

aKMnO₄ + bHCl Œ aKCl + aMnCl₂ + xH₂O + yCl₂

The n^th term of a sequence is .

The diagram shows a crane that lifts a load with a mass of 100 kg at a constant speed of 0.4 m/s for 5 seconds. (g=10 N/kg)

Here are 3 statements about this activity:

1. The gain in gravitational potential energy of the load is 2000 J.

2. The tension in the cable at point P is 2000 N.

3. The load accelerates at 10 m/s².

The graph shows oxygen supply and demand in muscle cells during exercise.

Which one of the following would not be formed by cracking the hydrocarbon C₁₂H₂₆?

Here are four statements about radioactivity:

1. A beta particle is an electron that is emitted from the outermost electron shell of an atom.

2. A beta particle is emitted from the nucleus of the atom when a proton changes into an electron.

3. A beta particle is emitted from the nucleus of the atom when a neutron changes into an electron.

4. After a beta particle is emitted the mass number of the nucleus of the atom is unchanged.

During the breakdown of a solution containing carbohydrates, proteins and lipids by carbohydrase, protease and lipase enzymes, the pH changed from neutral due to the products formed.

In the diagram below, the triangles are congruent, PQ is a continuation of NL and both L and P are equidistant from the line X = 0 and from the line Y = 0.

1. Reflection in the line y = 0

2. Rotation of 90º about the origin

3. Reflection in the line y = x

4. Reflection in the line x = 0

5. Rotation of 180º about the origin

In the manufacture of hydrogen from methane and steam, carbon monoxide is produced as an unwanted side product. The amount of carbon monoxide is reduced by mixing the gases with steam when the following reversible reaction takes place.

CO (g) + H₂O (g) ↔ CO₂ (g) + H₂ (g)     ∆H negative (exothermic)

A car is accelerated from rest along a horizontal road by a constant thrust force produced by the engine. The car eventually reaches a terminal speed, and the graphs below show the variation with time of three quantities (X, Y and Z) for the car:

A right-angled triangle is shown.

The reflex arc enables the body to make rapid responses to certain stimuli.

The general formula for the alkane series is C_nH_2n+2

The amide series has the same saturated structure as the alkanes but with one H substituted by the -CONH₂ group.

I stop while out walking and take the bearing of a windmill and note it as θ º. I then walk 5 km north and take the bearing again – it is now 2 θ.

The diagram below shows three identical resistors and a battery that supplies a constant 12 V.

With the switch open, as shown, the current in resistor Y is 20 mA.

The four statements are about the movement of blood during one complete circuit of the body.

1. Blood flowing from the lungs flows through the heart twice.

2. All the blood flowing from the lungs flows through the kidneys.

3. All the blood flowing from the liver flows through the lungs.

4. Only blood flowing from the digestive system flows through the liver.

In addition to diamond and graphite, another allotrope of carbon is Buckminster fullerene, C₆₀, which is in the shape of a sphere.

A lorry of mass m, and travelling initially at speed v along a horizontal road, is brought to rest by an average braking force F in time t.

A quadratic equation has solutions a and b.

a + b = -5                           ab = 3

Red-green colour blindness is a condition caused by a recessive allele. The gene is carried on the X chromosome.

A sample of an alkali XOH of mass 2.8 g was dissolved in water.

This solution was neutralised by 12.5 cm³ of sulphuric acid of concentration 2.0 mol dm^-3.

2 XOH (aq) + H₂SO₄ (aq)  → X₂SO₄ (aq) + 2 H₂O (l)

Taking the speed of sound in air as 300 m/s and in steel as 4800 m/s. A worker lies next to a railway line and hears the whistle of a train through the steel rails and 1.5 s later hears the same whistle through the air.