Mole & Avogadro Constant The Avogadro constant (NA or L) is the number of particles equivalent to the relative atomic mass or molecular mass of a substance The Avogadro constant applies to atom...
Relative Masses Atomic Mass Unit The mass of a single atom is so small that it is impossible to weigh it directly Atomic masses are therefore defined in terms of a standard atom which is called the...
Structure of an Atom All matter is composed of atoms, which are the smallest parts of an element that can take place in chemical reactions Atoms are mostly made up of empty space around a very smal...
Recombinant DNA Technology Recombinant DNA The genetic code is universal, meaning that almost every organism uses the same four nitrogenous bases – A, T, C & G. There are a few exceptions The g...
Genome Sequencing Projects A genome contains all of the genes within an organism Advances in technology have allowed scientists to map and sequence the genes within an organism's genome Genome sequ...
Totipotent Cells A stem cell is a cell that can divide (by mitosis) an unlimited number of times Each new cell that is produced when a stem cell divides has the potential to remain a stem cell or t...
Gene Mutations A gene mutation is a change in the sequence of base pairs in a DNA molecule that may result in an altered polypeptide Mutations occur continuously and spontaneously Errors in the DNA...
The Definition of a Community Species do not exist by themselves in their own isolated environment, they interact with other species forming communities A community can be defined as: Multiple popu...
ISEF 国际科学与工程大奖赛（Regeneron ISEF）是全球最大规模、最高等级、也是唯一面向9-12年级（即初三至高三）中学生的科学学术活动，每年在美国的不同城市举行。 学术活动学科包括了所有自然科学和部分社会科...
2022-2023年SAT/ACT标化考试时间汇总！时间不等人，一定要提前做好准备！ ACT考什么、怎么考？ 很多初次接触ACT考试的学生和家长都不了解ACT具体考什么、怎么考。下面简单介绍一下考试。 ACT考试采取电脑考试的方...
Edexcel IGCSE Maths复习笔记 1.9.1 Compound Interest What is compound interest? Compound interest is where interest is paid on the interest from the year (or whatever time frame is being used) befor...
择校期一到，许多家长便浏览国际化学校网站、公众号、教育论坛，以获悉学费、课程、师资、位置、录取情况……择校展作为国际化学校和家长沟通的重要渠道，可近距离、更直接地家校了解。目前，南京民办校已陆续发布...
