By Angela Harrison
BBC News education reporter
The government says standards are rising
Standards in science exams in UK schools have been eroded and the system is failing a generation, the Royal Society of Chemistry warns.
In an online petition to Downing Street, the body says record-breaking exam results are "illusory".
So far 1,600 people have signed the petition, which complains that even bright students with enthusiastic teachers have to "learn to the test".
The government says standards in science have improved year on year.
According to the Royal Society of Chemistry, pupils are drilled to answer "undemanding questions to satisfy the needs of league tables and national targets".
They are not learning how to solve problems, use critical thinking or apply mathematics in science, its petition says.
On Thursday, every MP - as well as chief executives of FTSE 350 companies, schools and universities - will receive a report from the society which it says will "demolish the myth of record-breaking science education performance".
The report will include details of an "experiment" into standards in science exams staged by the RSC earlier this year. The society set students an exam made up of questions from papers set over the past five decades.
The students scored highest on the most recent questions and worst on those from the 1960s.
Chief executive Richard Pike said: "The target of our campaign is a failed education system, not the youngsters it's supposed to serve.
"We know that enthusiastic teachers are being compelled to 'teach to the test' to meet the demands of school league tables which draws mainly on the recalling of facts, with no reference to logic or mathematics.
"That means the brightest pupils are not being stretched, or trained in mathematical techniques, because they can get a grade A* without doing a single calculation.
"Conversely, the majority get at least a 'good pass' (grade C) by showing merely a superficial knowledge on a wide range of issues, but no understanding of the fundamentals. A mark of 20% was sufficient in one of this summer's GCSE science examinations."
In the new science GCSE - taken by the majority of students - 59% were awarded a C grade or higher according to provisional results for this year.
Students can opt to take additional science on top of this. In 2008, there were 537,606 entries for the new science GCSE and 433,468 entries for the additional GCSE.
Many able students opt to take the sciences separately where this is offered at their schools, and exam results are particularly high in these distinct subjects.
Analysts say this is because of the high ability of such candidates.
This year, 94% of students got a C or higher in chemistry, according to provisional figures, up from 91% last year. There were 76,656 entries for the exam.
The Westminster government insists standards in science are rising, not falling.
A spokeswoman for the DCSF said: "Standards in science have improved year on year thanks to ten years of sustained investment and improvement in teaching and the education system - this is something we should celebrate, not criticise.
"Exam standards are rigorously maintained by independent regulators and we would rather listen to the experts whose specific job it is to monitor standards over time.
"Ofsted say that the quality of teaching has improved. In Pisa 2006, a major international study on science, UK teenagers did well above the OECD average on science and the UK was in the group of 'higher achieving' countries."
The official added that the aim today was for all young people to have a thorough grounding in chemistry, physics and biology but also "to be able to apply it to the science of climate change, stem research and understand how it impacts on and shapes the world we live in".
'Illusory leap forward'
Shadow Children's Secretary Michael Gove said: "The Royal Society of Chemistry is only the latest independent body to warn of the devaluation of science education.
"We've slipped 10 places in the international league tables for science and children are being asked questions that show our curriculum isn't preparing them for the challenges for the 21st century.
"That's why we need to make sure that our exams are as good as the world's best."
Dr Pike, from the RSC, added: "We are witnessing an illusory great leap forward in education, where achieving contrived targets has become the end in itself.
"The proof lies in the enormous expense to provide remedial mathematics and even remedial science classes at university, and the lack of skills of graduates highlighted by employers."