Which of the following elements is unlike the other elements, due to its classification on the periodic table?

• Nitrogen

• Cobalt

• Chlorine

• Xenon

Tags

NGSS.HS-PS1-1

What atom below would consist of two protons in its nucleus?

• Helium

• Hydrogen

• Lithium

• Boron

The goal of alchemists was to transform lead into gold and silver. Why would scientists today view alchemy as false science?

• Alchemists were not successful in transforming lead despite many attempts

• Modern scientists have attempted the same and still are unable to do so.

• Alchemist used incantation and rituals in their experiments

• The law of definite proportions states that the number of atoms in lead cannot be changed to make gold.

Tags

NGSS.HS-PS1-7

The term for atoms of the same element that have the same atomic number but different mass numbers.

• Ions

• Isotopes

• Neutrinos

• Quarks

Which of the following observations is not an indication that a chemical reaction has taken place

• Gas bubbles when powder is added

• A solid material becomes liquid when it is heated

• Heat is generated when sodium is exposed to water

• Water forms when hydrogen burns in the presence of oxygen

What statement below best describes Bohr’s model of the hydrogen atom?

• The electron is in circular orbitals (energy levels) around the nucleus

• A large, dense nucleus surrounded by atoms in different orbits.

• A nucleus surrounded by orbiting neutrons

• All the particles are mixed together like plum pudding

What type reaction is show below 2Al + ZnO3 --> Zn + Al2O3

• Double replacement

• Single replacement

• Synthesis

• Combustion

In a reaction in which heat is transferred from the system to its surroundings is known as a __________ reaction.

• Exothermic

• Endothermic

• Endoscopic

• Endergonic

Tags

NGSS.HS-PS1-4

A student finds that 1.6 grams of CH4 will react with enough oxygen gas to produce 3.6 grams of water and 4.4 grams of carbon dioxide. Find the sum of the coefficients from the balanced chemical equation using the reaction above.

• 4

• 5

• 6

• 8

Tags

NGSS.HS-PS1-7

The data below shows the density of copper a student finds when doing a laboratory test. She compares this to the actual value in the Handbook of Chemistry and Physics to be 8.96 g/cm³. What was her percent error?

• 1.5%

• 98%

• 98.6%

• 99%