science

periodic table

100

iron=

fe

200

na=

sodium

300

cl=

chlorine

400

cs=

cesium

500

potassium=

k

bonds

100

Two nonmetals form a _____

covalent bond

200

in nonpolar covalent bonds, the electrons are_____

shared equally between the two atoms

300

How many bonds can carbon form with itself?

single double or triple bonds

400

Carbon forms _____ bonds with itself.

covalent

500

________ bonds have low melting points, are somewhat soluble in water, and are poor conductors of electricity.

covalent

matter

100

what is matter

anything with mass and volume

200

what are matters main states

solid liquid and gas

300

what makes up matter

atoms or molecules

400

how does matter behave

physical/chemical properties like density, reactivity

500

what causes changes in matter

 energy temperature and chemical reactions

temperature

100

What is temperature fundamentally?

Temperature is a measure of the average kinetic energy (energy of motion) of the particles (atoms and molecules) within a substance; higher temperature means faster-moving particles, while lower temperature means slower movement

200

What are the main temperature scales, and why do we have them?

1. We use Celsius (°C), Fahrenheit (°F), and Kelvin (K); Celsius is common globally (water freezes at 0°C), Fahrenheit for US weather, and Kelvin for science, as it starts at absolute zero (0 K).

300

What is absolute zero, and can we reach it?

Absolute zero (0 K or -273.15°C) is the theoretical point where all particle motion stops, but it's incredibly difficult to reach, though scientists get very close using specialized cooling methods. 

400

How does a thermometer work?

Most thermometers use thermal expansion: a liquid (like mercury or alcohol) or gas inside a tube expands when heated and contracts when cooled, with the level indicating the temperature.

500

How does temperature affect the world around us?

Temperature influences everything from the state of matter (ice to water to steam) and chemical reaction rates to weather, density, electrical conductivity, and the behavior of living organisms.

atoms

100

How do we know about atoms if they are so small, and what defines an element?

• Scientists infer atomic structure through experiments (like cathode ray tubes, scattering experiments) and theory, and an element is defined solely by the number of protons (its atomic number). 

200

Are two atoms of the same element identical?

• Not always; isotopes are atoms of the same element (same protons) with different numbers of neutrons, affecting their mass and stability but not usually their chemical behavior.

300

Do atoms ever actually touch each other?

no they dont in a solid sense

400

Why don't atoms collapse or electrons fly away?

• Electrons don't behave like planets; they exist in probability clouds (orbitals) governed by quantum mechanics, and the electromagnetic attraction to the positive nucleus keeps them bound.

500

What are the basic components of an atom, and what holds them together?

1. 
   
   • Atoms have a central nucleus (protons with positive charge & neutrons with no charge) and orbiting electrons (negative charge). The strong nuclear force binds the nucleus, while electromagnetic attraction holds electrons to the nucleus, despite proton repulsion.