Theory

CH11 - ATOMS AND RADIOACTIVITY

A certain element is known to exist as two different isotopes.(a) State one thing that is the same for atoms of both isotopes............................

2010 Summer

2

Theory

CH11 - ATOMS AND RADIOACTIVITY

Emissions from a radioactive source pass through a hole in a lead screen and into a magnetic field, as shown in Fig. 10.1. Radiation detectors are p...

2010 Winter

1

Theory

CH11 - ATOMS AND RADIOACTIVITY

(a) An atom consists of a nucleus made up of protons and neutrons, surrounded by orbiting electrons.(i) Which of these particles has a positive charge...

2011 Summer

1

Theory

CH11 - ATOMS AND RADIOACTIVITY

A scientist needs to use a source of $\gamma$-rays as safely as possible.Which action will not reduce the amount of radiation that reaches the scienti...

2011 Winter

2

Theory

CH11 - ATOMS AND RADIOACTIVITY

A nuclide of substance X has the symbol $^{26}_{12}X$.How many electrons are there in a neutral atom of substance X?A. 12 B. 14 C. 26 D. 38

2011 Winter

2

Theory

CH11 - ATOMS AND RADIOACTIVITY

The graph shows the activity of a radioactive source over a period of time. What is the half-life of the source? A $\frac{1}{2}$ hour B 1 hour C ...

2011 Winter

3

Theory

CH11 - ATOMS AND RADIOACTIVITY

A radioactive nucleus contains 138 neutrons. The nucleus emits an \( \alpha \)-particle. How many neutrons are in the nucleus after it has emitted th...

2009 Summer

2

Theory

CH11 - ATOMS AND RADIOACTIVITY

The graph shows the decay curve for one particular radioactive nuclide. What is the half-life of this nuclide? A. 1.0 day B. 1.5 days C. 2.0 days D. ...

2009 Summer

2

Theory

CH11 - ATOMS AND RADIOACTIVITY

Which diagram could represent the structure of a neutral atom?[Image_1: Diagrams A, B, C, and D with key indicating neutron, proton, electron]

2012 Summer

2

Theory

CH11 - ATOMS AND RADIOACTIVITY

A radioactive element has a half-life of 70s.The number of emissions per second, $N$, of a sample of the element is measured at a certain time.What wa...

2010 Winter

1

Theory

CH1 - MEASUREMENTS AND UNITS

A geologist compares the volumes of three rocks, X, Y and Z. Three measuring cylinders contain different volumes of water. He places each rock into on...

2015 Summer

Theory

CH2 - FORCES AND MOTION

A car moves with constant speed and then constant acceleration.Which graph is the speed-time graph for the car?[Image_1: Graphs A, B, C, D]

2015 Summer

Theory

CH2 - FORCES AND MOTION

A car travels 100 km. The journey takes two hours. The highest speed of the car is 80 km/h, and the lowest speed is 40 km/h. What is the average spee...

2015 Summer

Theory

CH2 - FORCES AND MOTION

Diagram 1 shows a piece of foam rubber that contains many pockets of air. Diagram 2 shows the same piece of foam rubber after it has been compressed s...

2015 Summer

Theory

CH1 - MEASUREMENTS AND UNITS

A metal block has the dimensions shown. Its mass is 1000 g.What is the density of the metal?A $\left(\frac{5 \times 10}{1000 \times 2}\right)$ g/cm$^3...

2015 Summer

Theory

CH3 - FORCES AND PRESSURE

Four objects are each acted on by only two forces, as shown.Which object is in equilibrium?

2015 Summer

Theory

CH3 - FORCES AND PRESSURE

A student measures the length of a spring. She then hangs different weights from the spring. She measures the length of the spring for each different ...

2015 Summer

Theory

CH4 - FORCES AND ENERGY

Which energy resource is used to generate electricity without using any moving parts?A. geothermalB. hydroelectricC. nuclearD. solar

2015 Summer

Theory

CH4 - FORCES AND ENERGY

A cyclist travels down a hill from rest at point X, without pedalling.The cyclist applies his brakes and the cycle stops at point Y.Which energy chang...

2015 Summer

1

Theory

CH3 - FORCES AND PRESSURE

The diagram shows a simple mercury barometer.Which height is used as a measurement of atmospheric pressure?

2015 Summer