PS Apex Unit 3 Test Review

How was Bohr's atomic model different from those of previous scientists?

• It showed that electrons could jump from one path to another.

• It included positive and negative parts.

• It showed that electrons were located outside the nucleus.

• It included a nucleus.

The diagram shows a model of an atom. Who first proposed this model?

• Rutherford

• Dalton

• Bohr

• Thomson

Which two particles are always found in equal numbers in neutral atoms?

• Protons and electrons

• Protons and neutrons

• Electrons and neutrons

• Neutrons and ions

What is one characteristic of an electron?

• Almost no mass

• Almost no charge

• A mass of 1 amu

• A charge of +1

The box shows the element helium as it appears in the periodic table. Which list gives the correct numbers of subatomic particles for a neutral atom of helium?

• Two protons, two neutrons, two electrons

• Four protons, four neutrons, four electrons

• Two protons, two neutrons, four electrons

• Two protons, four neutrons, six electrons

The box shows the element beryllium as it appears in the periodic table. How many protons and electrons does a neutral atom of beryllium have?

• Four protons, four electrons

• Two protons, two electrons

• Four protons, five electrons

• Nine protons, nine electrons

Based on their chemical formulas, which of these common substances is an element?

• Gold (Au)

• Salt (NaCl)

• Water (H₂O)

• Sugar (C₆H₁₂O₆)

Oxygen gas is made of molecules like the one this model shows. Which chemical formula most likely describes oxygen gas?

• O₂

• OO

• O₁₀₀

• O_G

Which two types of information are found in an element's box in the periodic table?

• Chemical formula and symbol

• Chemical symbol and Atomic number

• Atomic structure and number

The diagram shows the box for the element krypton in the periodic table. What is the chemical symbol for this element?

• Kr

• Kryptonite

• k

• Krypton