1.02

Which best explains why a washing machine represents an open system?

• Water and power come from external sources.

• The amount of wash in a load varies

• It has multiple cycles, such as wash and spin.

• Most washers can use a variety of laundry detergent brands.

Why is the law of gravity an example of a universal law?

• Gravity is the attraction of any mass to any other mass.

• Gravity is a force that affects everyone on Earth

• Gravity is the reason the Earth revolves around the sun.

• Gravity is a force that exists between any two masses in the universe.

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NGSS.MS-ESS1-2

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Which statement best defines a universal law?

• It is in effect at all times.

• It operates only under specific conditions.

• It is in effect some of the time.

• It changes over time.

The model of the atom has changed over time in light of new knowledge and discoveries. Which option correctly describes one such change?

In 420 B.C., John Dalton developed the idea that small atoms combined to form molecules.

• In 420 B.C., John Dalton developed the idea that small atoms combined to form molecules.

• About 1900, Neils Bohr developed an atomic model where positively charged particles orbit a negatively charged nucleus.

• About 1900, J.J. Thomson discovered electrons were negatively charged particles.

• About 1915, J.J. Thomson developed an atomic model where negatively charged particles orbit a positively charged nucleus.

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NGSS.MS-PS1-1

Our understanding of the atom has changed over time. Which idea that was once accepted is now considered scientifically inaccurate?

• The nucleus is the center of the atom.

• An atom is a solid sphere

• Electrons have a negative charge.

• Electrons are arranged in layers.

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NGSS.MS-PS1-1

All living things are made up of...

• cells

• cell tissues

• organ

• organ systems

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NGSS.MS-LS1-1

Cells are often called "the ____ of life."

• bread

• road map

• building blocks

• meaning

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NGSS.MS-LS1-1

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When observing cells, which of the following pieces of equipment is most appropriate?

• Hand lens

• Telescope

• Petri dish

• Microscope

Why are microscopes important when studying most cells?

• Most cells are very large.

• Most cells are very small.  

• Most cells move very quickly.

• Most cells are dead.  

What is the significance of the number 1.02 in the context of density?

• It represents the density of water in g/cm³.

• It represents the density of air in g/cm³.

• It represents the density of a typical human cell in g/cm³.

• It represents the density of mercury in g/cm³.