TEKS 8.11abc

A chemist is identifying the elements present in a sample of seawater. What characteristic of an element’s atoms always determines the element’s identity?

• The number of neutrons

• The number of protons

• The location of valence electrons

• The number of valence electrons

How do electrons of an element determine that element's reactivity?

• If the valence shell has missing electrons it is very reactive to attract or lose more electrons.

• If the valence shell has a full ring of electrons it is very reactive because it needs more.

• If the valence shell has a full shell of electrons it is very reactive because it is already full.

• If the valence shell has missing electrons it is not reactive because it is missing electrons.

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NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following properties of carbon distinguishes it from all other elements?

• Carbon has six protons in its nucleus

• Carbon forms compounds with oxygen

• Carbon is a gray solid at room temperature

• Carbon can be found in Earth’s crust

An element’s reactivity and other chemical properties are determined by the number of -

• isotopes it has.

• oxidation states.

• valence electrons.

• orbitals in an atom.

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NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following properties uniquely identifies every element?

• Number of valence electrons

• Charge of the atom

• Number of neutrons

• Number of protons

Valence electrons are electrons in the shell

• furthest from the nucleus

• closest to the nucleus

• having the lowest energy level

• that has the fastest electrons

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NGSS.HS-PS1-1

NGSS.HS-PS1-2

All atoms are most stable with (or would "prefer") how many electrons in their valence shell?

• 1

• 2

• 8

• 18

Which of the following is a characteristic of a chemical change?

• A change in state

• A change in color

• A change in shape

• A change in temperature

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NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is the primary function of the mitochondria in cells?

• Photosynthesis

• Protein synthesis

• Energy production

• Cell division

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NGSS.MS-LS1-7

NGSS.MS-LS1-2

Which of the following best describes the process of osmosis?

• Movement of water from high to low concentration

• Movement of solutes from low to high concentration

• Movement of water from low to high concentration

• Movement of solutes from high to low concentration