# Chemistry by Leah

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🇬🇧 | 🇬🇧 |

Hypotheses need to be based on… | Observations |

What is the scientific difference between a hypothesis and a theory? | The amount of evidence by which they are supported |

Essentially, a hypothesis is a... | Conjecture |

Scientific theories are supported by... | Substantial evidence |

What is a Hazard? | Something that could potentially cause harm |

To ensure the results of your investigation are reproducible, you can compare them by taking another set of readings using? | Different equipment |

Which type of model uses words to describe the features of a system and how they interact | Descriptive |

A mathematical model that needs a computer to carry out complex calculations defines a ___ model | Computational |

____ are used in the study of earthquakes | Computational models |

If you add together all your data values and divide by the total number of values in the sample, what data will you be collecting? | The mean (average) |

In a calculation the first significant figure of a number is… | The first digit that is not zero |

In a calculation you should always round the numbers to the… | Lowest number of significant figures |

The first significant figure in a number reads from… | Right to left |

The trailing zeros in a whole number are… | Significant |

The leading zeros in a decimal are… | Not significant |

What do you call the slope in a linear graph? | The gradient |

How do you calculate the gradient? | Gradient = change in y / change in x |

Your mum | Your mum answer |

The SI base unit of candela (cd) is used to measure the quantity of? | Luminous intensity |

The SI base unit of mole (mol) is used to measure the quantity of? | Amount of substance |

To convert from bigger units to smaller units do you divide or multiply by the conversion factor? | Multiply |

To convert from smaller units to bigger units do you multiply or divide by the conversion factor? | Divide |

Prefixes are intended to to create appropriately sized units to ensure the numbers are read much... | Easier |

The multiplication factor for Tera is 10¹². Write the multiplication factor numerically. | 1 000 000 000 000 |

The multiplication factor for Giga is 10⁹. Write the multiplication factor numerically. | 1 000 000 000 |

The multiplication factor for Nano is 10⁻⁹. Write the multiplication factor numerically. | 0.000 000 001 |