Atoms

Which of these is not part of an atom?

• proton

• isotope

• nucleus

• electron

Very energetic particles that move in all directions around the nucleus of an atom are

• protons

• electrons

• neutrons

• charges

Which of these particles has a positive charge?

• atom

• proton

• electron

• neutron

Carbon atoms have 6 protons and 6 neutrons in the nucleus. They also have 6 electrons outside the nucleus. What is carbon's atomic mass?

• atomic number = 12; atomic mass = 12

• atomic number = 6; atomic mass = 18

• atomic number = 6; atomic mass = 12

• atomic number = 12; atomic mass = 18

All metallic elements are

• powdery solids

• good thermal insulators

• good conductors of electricity

• easily melted into liquids

The element beryllium (Be, atomic number 4 and atomic mass 9) is right above magnesium (Mg, atomic number 12 and atomic mass 24) on the periodic table. How many more electrons does magnesium have than beryllium?

• 5

• 7

• 8

• 15

Which elements are represented by the symbols NaCl?

• sodium, chlorine

• sodium, oxygen, hydrogen

• hydrogen, chlorine

• chlorine, oxygen

On the periodic table, nitrogen is represented by N (atomic number 7) N is a chemical

• equation

• period

• symbol

• group (family)

Across a period of eight elements in the periodic table, the number of valence electrons

• is the same for all eight elements

• is equal to the period's number

• increases from 1 to 8

• depends on the atomic numbers of the elements

Copper (Cu) is a transition metal found in the 11th column of the periodic table. What statement is true about copper and the two other elements in that column?

• All three elements are nonreactive.

• All three elements are in the same period.

• All three elements have the same number of protons.

• All three elements have similar chemical properties.