chemistry

Why is carbon an element and not a compound?

• All carbon atoms have the same number of protons.

• Carbon bonds easily with oxygen, but not helium

• Carbon is found in all living things

Each of the elements in the periodic table has a specific number. What does the number represent?

• the half-life

• the number of neutrons

• the number of protons

Water evaporating from salt-water is what kind of change?

• Physical change

• Chemical Change

Which process is most effective for separating sodium chloride from a saltwater solution?

• filtration

• evaporation

• magnetic separation

• chemical separation

A chemist is looking for an element that reacts similarly to the element lithium (Li). Which would be the best choice?

• gold (Au)

• neon (Ne)

• fluorine (F)

• sodium (Na)

Which element has 7 valence electrons?

• hydrogen (H)

• fluorine (F)

• lead (Pb)

If an element has no electrons to share and is stable, what family is it found in?

• alkali metals

• noble gases

• halogens

Which best explains how elements are arranged on the modern periodic table?

• Elements are arranged from fewest protons to most protons

• Elements are arranged from most protons to fewest protons

• Elements are arranged from fewest neutrons to most neutrons

Which best describes a row of elements in the periodic table?

• column

• family

• group

• period

In which groups did Mendeleev most likely place highly-reactive elements?

• IA and VIIA

• IA and VIIIA

• IIA and VIIIA