materMaterials and Processes in Design
Unit 1 Assignment 2
Alicia Gingrich

1. The three basic components of an atom are protons, neutrons, and electrons. While protons hold a positive charge, electrons hold a negative charge and neutrons hold no charge whatsoever. Protons and neutrons occupy the center of an atom called the nucleus while electrons maintain orbits around the nucleus.

2. The four types of bonding arrangements of atoms are; ionic, covalent, metallic, and Van der Waals bonding. An ionic bond links different types of atoms through the attraction between positive and negative charges, similar to the way magnets work. While these bonds are generally not conductive many are soluble and will conduct electricity once combined with water. Covalent bonds are made when atoms share their ‘valence’ electrons. Valence electrons occupy the third orbit of an atom. A metallic bond is created among metallic atoms when some of the valence electrons separate and exist in a free state. The Van der Waals bond is created between neutral atoms. This bond is the secondary bond found in the long chains of large molecules that make polymers.

3. Larger grained metals are more plastic and ductile. The smaller the grain the harder a metal will become; thus, larger grains are much easier to deform. Grain size can be made smaller by more rapid cooling to harden a metal once one is finished shaping it.

4. Thermoplastics and thermosets can withstand a high amount of stress before the strain reaches a breaking point. Both have a high elasticity. The biggest difference between thermoplastics and thermosets is that thermoplastics can be re-melted while thermosets will just char. Because thermoplastics can be re-melted they can be recycled/ repurposed.

5. The process that hardens Portland cement is called hydration and hardening. Portland