Hmmmmmmmmmmmmmmmmm Flashcards
(25 cards)
What is the particle theory of matter?
Matter is made up of tiny particles, particles are in constant motion, particles are held together by attractive forces, there are spaces between particles, adding heat increases the motion of particles.
Diagrams can show particle arrangement in solids, liquids, and gases, helping to visualize their behavior.
How are substances classified based on their properties?
Substances are classified based on physical properties (color, state, density, boiling/melting point) and chemical properties (reactivity, combustibility, ability to rust).
Define qualitative physical properties and provide examples.
Qualitative physical properties are characteristics that can be observed but not measured, such as color (blue) and texture (rough).
Define quantitative physical properties and provide examples.
Quantitative physical properties are characteristics that can be measured, such as density (1.00 g/mL) and boiling point (100°C).
What are chemical properties?
Chemical properties describe a substance’s ability to undergo a chemical change, such as reactivity with acid (produces hydrogen gas), combustibility (ability to burn), and reactivity with iodine (forms a blue-black complex).
What is the formula for density?
Density = Mass ÷ Volume.
What are the units for measuring density?
Big units: g/L, kg/m³; Small units: g/cm³, mg/mL.
Using the G.R.A.S.S. method, what is the required analysis for density?
Given: Mass = 50 g, Volume = 10 mL; Required: Density; Analysis: Use Density = Mass ÷ Volume.
What is the periodic table?
The periodic table organizes elements by increasing atomic number.
Define periods and groups in the periodic table.
Periods are horizontal rows (indicate the number of electron shells); Groups are vertical columns (elements in the same group have similar properties).
How would you outline a blank periodic table for atomic numbers 1–20?
Draw a grid with 7 periods and 18 groups; Label elements by symbol and atomic number (e.g., H = 1, He = 2).
Highlight key chemical families on the periodic table.
Alkali metals: Group 1, very reactive, 1 valence electron; Alkaline earth metals: Group 2, reactive, 2 valence electrons; Halogens: Group 17, nonmetals, very reactive; Noble gases: Group 18, inert, full valence shells.
Compare Dalton’s atomic theory.
Dalton: Atoms are indivisible and identical for each element.
What did Thomson contribute to atomic theory?
Thomson discovered electrons and proposed the ‘plum pudding’ model.
What did Rutherford discover?
Rutherford discovered the nucleus and proposed the nuclear model.
What is Bohr’s contribution to atomic theory?
Bohr proposed that electrons orbit the nucleus in fixed energy levels.
What is a Bohr-Rutherford diagram?
A diagram that shows the arrangement of electrons in shells around the nucleus.
How do Bohr-Rutherford diagrams differ between neutral and stable atoms?
Neutral atom: Equal number of protons and electrons; Stable atom: Full valence shell.
Explain trends in groups on the periodic table.
Groups have the same number of valence electrons and similar chemical properties.
Explain trends in periods on the periodic table.
Periods show increasing energy levels and atomic size as you go down.
What test identifies oxygen gas?
Oxygen relights a glowing splint.
What test identifies carbon dioxide gas?
Carbon dioxide turns limewater cloudy.
What test identifies hydrogen gas?
Hydrogen produces a ‘pop’ sound with a lit splint.
Identify the three subatomic particles.
Proton: Positive charge (+), in nucleus; Neutron: Neutral charge (0), in nucleus; Electron: Negative charge (-), in orbitals.
