Science T4 2024

What are the smallest units of matter consisting of protons, neutrons, and electrons called?

Atoms

What particles are positively charged and found in the nucleus of an atom?

Protons

What are the neutral particles found in the nucleus called?

Neutrons

What negatively charged particles orbit the nucleus in energy levels?

Electrons

What is the central core of an atom containing protons and neutrons?

Nucleus

What are the fixed distances from the nucleus where electrons are likely to be found?

Energy Levels

What was the primary idea of Dalton's model of the atom?

Proposed atoms as solid spheres.

What concept did Thomson's model introduce about the structure of the atom?

Electrons are embedded in a positively charged 'soup' (plum pudding model).

What did Rutherford's model reveal about the atom?

Discovered the nucleus, indicating that atoms have dense nuclei and are mostly empty space.

What regions around the nucleus indicate where electrons are likely to be found?

Electron Orbitals

How are elements arranged in the Periodic Table?

Based on increasing atomic number.

What is the atomic number?

The number of protons in an atom's nucleus.

What do rows in the Periodic Table indicate?

The number of electron shells an atom has.

What do columns in the Periodic Table display?

Elements with similar chemical properties due to similar electron configurations.

Who is credited with the first Periodic Table and what was his approach?

Dmitri Mendeleev; organized elements by atomic weight.

How is the modern Periodic Table organized?

By atomic number and electron configuration.

What are ionic compounds formed by?

The transfer of electrons between atoms.

What are charged particles resulting from the loss or gain of electrons called?

Ions

Provide an example of an ionic compound.

Sodium chloride (NaCl).

What force holds oppositely charged ions together in an ionic bond?

Electrostatic Attraction.

How do covalent compounds form?

When atoms share electrons.

What are molecules formed from?

Covalent bonds.

Provide an example of a covalent compound.

Water (H2O).

What does polarity describe in a molecule?

The distribution of electrical charge across a molecule, leading to dipoles.

What is a primary application of nuclear research in energy?

Using nuclear fission to generate electricity.

How is radiation therapy beneficial in medicine?

It is employed in cancer treatment.

What fundamental processes does nuclear research enhance our knowledge of?

Processes in physics and chemistry.

What does nuclear chemistry study?

Chemical reactions involving atomic nuclei.

What is the process of combining lighter nuclei to form heavier nuclei called?

Fusion.

What is the primary reaction in stars where hydrogen forms helium?

Hydrogen Fusion.

What does the Big Bang Theory explain?

The origin of the universe from a singularity.

What is the continuous growth of the universe since the Big Bang referred to as?

Expansion.

What evidence supports the Big Bang Theory?

Cosmic microwave background radiation and redshift studies of galaxies.

What is accretion in space?

The process by which dust and gas clump together under gravity to form larger celestial bodies.

What are regions in space called where dust and gas are dense enough to lead to star formation?

Molecular Clouds.

What are small celestial objects formed from dust and gas debris that build up to create planets called?

Planetesimals.

What events contribute to the formation of heavier elements during a star's lifecycle?

Stellar Processes.