TEKS 8.5B

In order to determine what this atom is, you must look at it's -

• electrons

• neutrons

• atomic mass

• protons

A student is studying calcium, a highly reactive element that humans need for strong bones. Which characteristic of calcium is most closely related to its chemical reactivity?

• The 20 protons in each atom of calcium

• The electrons in each atom of calcium

• The atomic mass of calcium, which is 40.078 amu

• The density of calcium, which is 1.54 g/cm3

An atom consists of 12 protons, 12 electrons, and 12 neutrons. Which of the following can be used to identify the element?

• Neutrons

• Electrons

• Atomic number/protons

• Atomic mass

An atom has 11 protons, 12 neutrons, and 11 electrons. What is the identity of the element?

• Sodium

• Titanium

• Vanadium

• Magnesium

Tags

NGSS.MS-PS1-1

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

What part of an atom is involved in chemical reactions?

• Neutrons

• electrons

• protons

• atomic mass

Four students were asked to name the parts of an atom that determine the atom’s identity and chemical properties. The students’ responses are shown in the table below.

• Student 1

• Student 2

• Student 3

• Student 4

Tags

NGSS.MS-PS1-1

How many electrons does the atom of Carbon-14, shown above have?

• 14

• 10

• 6

• 4

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

Tags

NGSS.MS-PS1-1

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

• isotopes it has.

• oxidation states.

• electrons.

• orbitals in an atom.