Atoms (SI)

Which of the following statements is true about the lithium and the helium atoms?

• Lithium has more protons, neutrons, and electrons.

• There is no difference between helium and lithium.

• Helium has more protons, neutrons, and electrons.

• Lithium is much smaller than helium.

Tags

NGSS.MS-PS1-1

In this model of an atom the blue dots represent electrons, and the red dot represents the nucleus. This model accurately represents

• that the nucleus is located at the center of the atom.

• what an atom would look like when seen through a microscope.

• that electrons are found everywhere in an atom, even in the nucleus.

• that a single atom may have many nuclei.

Tags

NGSS.MS-PS1-1

An atom with an equal number of electrons and protons has no ______.

• charge
• reactivity
• weight
• neutrons

Neutrons are neutral. This means that

• neutrons do not have a charge.
• neutrons are neither acidic nor basic.
• neutrons are not involved in chemical reactions.
• neutrons do not have mass.

An uncharged atom has six electrons. The nucleus of this atom must contain _______ protons.

• six
• eight
• seven
• five

Tags

NGSS.MS-PS1-1

The smallest particles that make up matter

• are too small to be seen with the unaided eye.
• are about the size of pinheads.
• can be seen with the unaided eye only at certain temperatures.
• are about the size of marbles.

Which of these is the part of an atom that contains the protons and neutrons?

• nucleus
• electron
• shell
• orbital

An atom has at least one positive proton and at least one negative electron. Which of the following is true about the protons and electrons in an atom?

• Protons and electrons are far apart with empty space in between.
• Protons and electrons orbit close together around a central nucleus.
• Protons and electrons are mixed together in a cloud.
• Protons and electrons are stuck together in neutral pairs.

Tags

NGSS.MS-PS1-1

Within an atom, electrons

• are in motion outside the nucleus.
• are outside the nucleus and are motionless.
• are in motion inside the nucleus.
• are inside the nucleus and are motionless.

What atoms are present in the molecule calcium carbonate (CaCO₃)?

• one calcium atom, one carbon atom, and three oxygen atoms

• one calcium atom, one carbon atom, and two oxygen atoms

• two calcium atoms, two carbon atoms, and three hydrogen atom

• one calcium atom and three carbon atoms

Tags

NGSS.MS-PS1-1