8th Grade Science EOG Practice

Fill in the blank: ______ are the basic building blocks of matter; very small, made of protons (+), neutrons (neutral), and electrons (-).

• Atoms

• Molecules

• Cells

• Compounds

Tags

NGSS.MS-PS1-1

Fill in the blank: ______ are pure substances made of only one type of atom; cannot be broken into simpler substances.

• Elements

• Compounds

• Mixtures

• Solutions

Fill in the blank: ______ are substances made of two or more elements chemically combined; can only be separated by chemical changes.

• Compounds

• Mixtures

• Elements

• Solutions

Fill in the blank: ______ are physical combinations of two or more substances that keep their own properties; can be separated by physical methods (filtration, sifting, evaporation).

• Mixtures

• Elements

• Compounds

• Atoms

Which type of mixture is described as substances that are not uniform; different parts can be seen (e.g., granite, soil, trail mix)?

• Heterogeneous

• Homogeneous

Which type of mixture is described as substances that are uniform and evenly mixed; parts cannot be seen (e.g., salt water, air, vinegar)?

• Heterogeneous

• Homogeneous

Atoms differ by number of ______ (atomic number), which defines the element.

• protons

• neutrons

• electrons

• isotopes

The Periodic Table arranges elements by increasing ______ number (left to right = periods).

• atomic

• mass

• group

• valence

Elements in the same ______ (column) have similar chemical properties.

• group

• period

• row

• block

Reactivity ______ moving left to right across a period.

• decreases

• increases

• remains the same

• doubles

Tags

NGSS.HS-PS1-2