A briefing document, which tells science teachers how to engage pupils’ interest, includes the suggestion that they “use ball-bearings to make tilt switches for bombs”.

Tilt switches, which are triggered by movement, are believed to have been used on the Bali bombs, which killed more than 190 people last month.

The bomb technology idea is one response to the decline in the number of pupils taking science subjects to A level and beyond.

The document is designed for children adjusting to the first year of secondary school — when they are most likely to lose interest in academic work. It is part of the wider Key Stage 3 strategy, leading up to national tests at 14.

The document includes a foreword by Estelle Morris, the former Education Secretary, in which she emphasises the need for more children to take an interest in science. The advice for teachers is listed under “strategies for extending pupils’ experience of science”.

Tilt switches are usually made of mercury, contained in a sphere with positive and negative terminii. When the mercury moves it closes the electrical circuit and triggers the device. Ball bearings, which collect on one side of the switch when moved, can also be used. Apart from bombs, the switches are used in burglar alarms and solar-powered lights.

Other tips in the document include testing gravestones and analysing a “murder scene” to discover whether real blood is present.

It says: “Visit a graveyard to look at weathering. Investigate which type of rock makes the best gravestone by collecting data on the age of the gravestone, the type of rock and the degree of weathering. A tyre gauge can help pupils to decide how much letters have been worn away and a dropper bottle of very dilute acid will help them to identify if the stone is marble or not.

“Murder mystery — analyse evidence from a crime scene and read statements from suspects to identify the murderer, eg, test pH of red mark to see if it’s real blood . . . match fingerprints and handwriting.”

It also suggests investigating crumple zones at the front of cars by making designs out of card, attaching them to trolleys and crashing them.

In her foreword Ms Morris says: “Science is diverse and exciting. It helps pupils to explore the world around them and understand so many things that have such relevance to daily life.” She adds that it is up to each school to make a professional judgment about how to use the advice.

“It is certainly diverse and exciting for potential terrorists,” Damien Green, the Conservative education spokesman, said yesterday. “It beggars belief that they could think this was appropriate guidance in the current climate.”

The decline in the popularity of science subjects at school has had knock-on effects throughout the economy: more than 30,000 university places to study science and engineering were left empty last year and the number of graduates recruited to teach science subjects has fallen by 23 per cent over five years.

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