Which of the following best describes an electron?

• It has no charge and about the same mass as a proton.

• It has a negative charge and much less mass than a proton.

• It has a positive charge and much more mass than a neutron

• It has a negative charge and about the same mass as a neutron

Tags

NGSS.MS-PS2-3

When trying to identify an unknown element, a student determines what other elements the unknown element reacts chemically. Which property of the unknown element determines the other elements it reacts with?

• The total number of neutrons in the unknown element

• The total number of particles in the nucleus of the unknown element

• The number of protons in the nucleus of the unknown element

• The number of valence electrons in the unknown element

A scientist spilled a few drops of dilute hydrochloric acid (HCl) on a lab table. For safety purposes, the scientist sprinkled some baking soda (NaHCO₃) onto the spill. Which observation would provide the best evidence that a chemical reaction occurred?

• The baking soda and hydrochloric acid combined and bubbles formed.

• the baking soda absorbed the hydrochloric acid

• Some of the baking soda dissolved in the hydrochloric acid

• The hydrochloric acid evaporated, leaving only the baking soda

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which information could a student determine from only the chemical formula of a protein?

• The color of the protein

• The number of molecules in each sequence that makes up a protein

• The physical arrangement of atoms in the structure of the protein

• The number of atoms of each element in the protein

Tags

NGSS.MS-PS1-1

The atoms of a certain element each contain 11 protons and 1 valence electron.

Which statement correctly identifies this element and describes its chemical reactivity?

• The element is sodium, and it is highly reactive

• The element is fluorine, and it is not very reactive

• The element is sodium, and it is not very reactive

• The element is fluorine and it is highly reactive

Which two elements on the periodic table are in the same period?

• Sn and Rb

• F and Cl

• K and Ba

• Se and Te

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

• H₃PO₄

• H₂SO₄

• HClO₃

• H₂O

Tags

NGSS.MS-PS1-1

Coal contains carbon and other elements. Carbon dioxide forms when coal burns in the presence of oxygen. Which of these is the best evidence that a chemical reaction occurs when coal burns?

• The shape of the coal changes

• Oxygen is present

• A new substance is produced

• Coal is made up of more than one element

Tags

NGSS.MS-PS1-2

An atom of a certain element has 36 protons, 36 electrons, and a mass number of 84. At room temperature this element is a very stable gas. How many neutrons are in this atom?

Tags

NGSS.MS-PS1-1

Aluminum, sulfur, and chlorine are elements found on the periodic table. Tests involving these three elements would show that at normal room temperature-

• Sulfur is malleable and aluminum conducts electricity

• Chlorine is malleable and conducts electricity

• Aluminum is malleable and conducts electricity

• all three elements are malleable and conduct electricity