Puberty typically begins between ages 9-11. Professor James M. Tanner identified visible puberty stages. Each person's puberty timeline differs
Solution is a homogeneous mixture of two or more substances. Solutions consist of solute dissolved in solvent. Solutions are stable and consist of single phase. Solution formation is physical, not chemical
Peak height was 6'4.12" (193.3cm) according to 361 votes. Some sources suggest he was 6'4.25" during his prime. Others believe he was 6'4.5" or slightly over in his prime
Old age is defined as 60 years or older by UN, 50 in developing countries. Western countries typically set retirement age at 65. Old age varies culturally and historically
Physical properties describe matter's state without changing its molecular structure. Intensive properties are independent of system size and material content. Extensive properties vary with matter amount and cannot identify substances
Matter is anything that occupies space, has mass, and consists of atoms. Matter exists in three states: solids, liquids, and gases. Particles of matter are constantly in motion and have spaces between them