Standard Bearer Academy

Neutron Electron Proton Photon

Atoms of different elements with the same mass Atoms of the same element with different numbers of electrons Atoms of the same element with different numbers of neutrons Atoms that have no neutrons

They have the same number of neutrons They have the same atomic mass They have the same number of valence electrons They were discovered at the same time

Covalent bond Metallic bond Ionic bond Hydrogen bond

Water molecules are perfectly symmetrical Oxygen and hydrogen share electrons equally Oxygen is more electronegative than hydrogen, creating an uneven distribution of charge Water has no electrical charge

Mass increases during chemical reactions Mass is neither created nor destroyed in chemical reactions Energy and mass are unrelated Atoms are destroyed and recreated during reactions

3.14 × 10¹⁰ — the ratio of a circle's circumference to its diameter 6.022 × 10²³ — the number of particles in one mole of a substance 9.8 — the acceleration due to gravity on Earth 1.66 × 10⁻²⁷ — the mass of one proton in kilograms

Neutral = 0; pH 3 = strongly basic Neutral = 7; pH 3 = strongly acidic Neutral = 14; pH 3 = weakly basic Neutral = 7; pH 3 = weakly acidic

An acid and a gas A salt and water A metal and an oxide Two new acids

It doesn't — pH regulation is a simple process that requires no design Blood pH varies widely and doesn't require precise control Multiple coordinated systems (buffers, lungs, kidneys) maintain a critically narrow range, pointing to purposeful engineering Blood pH is maintained purely by what we eat and drink