7th Grade Science Semester 1 Review

This set of flashcards covers key concepts related to density, chemical reactions, and digestive processes from the 7th Grade Science Semester 1 Review.

How do you calculate the density of an object?

Density is calculated by dividing the mass of the object by its volume.

What determines if a substance will sink or float in water?

A substance will sink if its density is greater than that of water (1 g/cm3) and float if its density is less.

What is the density of aluminum?

The density of aluminum is 3.7 g/cm3.

What type of change occurs when a firework is launched?

A chemical change occurs when a firework is launched.

What are the reactants in the chemical reaction of fireworks?

The reactants include Aluminum (Al) and potassium perchlorate (KClO4).

What is calcium carbonate's formula?

The chemical formula for calcium carbonate is CaCO3.

Why is the marble in the Taj Mahal deteriorating?

Chemical reactions with substances in contact with the marble, presumably due to pollution.

What happens to iron when it rusts?

When iron rusts, it weakens and can appear in different forms, like iron oxide.

What is the significance of the villi in the small intestine?

The height of the villi increases absorption efficiency due to more surface area for cells.

What condition might cause M’Kenna’s symptoms?

Possible conditions could involve malabsorption syndromes affecting nutrient uptake.

How do you calculate the density of an object?

Density is calculated by dividing the mass of the object by its volume.

What determines if a substance will sink or float in water?

A substance will sink if its density is greater than that of water (1 g/cm3) and float if its density is less.

What is the density of aluminum?

The density of aluminum is 3.7 g/cm3.

What type of change occurs when a firework is launched?

A chemical change occurs when a firework is launched.

What are the reactants in the chemical reaction of fireworks?

The reactants include Aluminum (Al) and potassium perchlorate (KClO4).

What is calcium carbonate's formula?

The chemical formula for calcium carbonate is CaCO3.

Why is the marble in the Taj Mahal deteriorating?

Chemical reactions with substances in contact with the marble, presumably due to pollution.

What happens to iron when it rusts?

When iron rusts, it weakens and can appear in different forms, like iron oxide.

What is the significance of the villi in the small intestine?

The height of the villi increases absorption efficiency due to more surface area for cells.

What condition might cause M’Kenna’s symptoms?

Possible conditions could involve malabsorption syndromes affecting nutrient uptake.

What defines a chemical change?

A chemical change is a process that involves rearrangement of the molecular or ionic structure of a substance, resulting in the formation of new substances.

What are some observable signs that a chemical change has taken place?

Common indicators include the production of gas (bubbles), formation of a precipitate, a change in color, a change in temperature, or the emission of light/heat.

What are the common units for density?

Density is commonly expressed in grams per cubic centimeter (g/cm^3) for solids and liquids, or grams per milliliter (g/mL) for liquids. Kilograms per cubic meter (kg/m^3) is also used.

What specific role do the cells lining the villi play in nutrient absorption?

The cells lining the villi contain enzymes for the final breakdown of carbohydrates and proteins, and actively absorb digested nutrients into the bloodstream or lymphatic system.

How do you calculate the density of an object?

Density is calculated by dividing the mass of the object by its volume.

What determines if a substance will sink or float in water?

A substance will sink if its density is greater than that of water (1 \text{ g/cm}^3) and float if its density is less.

What is the density of aluminum?

The density of aluminum is 3.7 \text{ g/cm}^3.

What type of change occurs when a firework is launched?

A chemical change occurs when a firework is launched.

What are the reactants in the chemical reaction of fireworks?

The reactants include Aluminum (Al) and potassium perchlorate (KClO4).

What is calcium carbonate's formula?

The chemical formula for calcium carbonate is CaCO3.

Why is the marble in the Taj Mahal deteriorating?

Chemical reactions with substances in contact with the marble, presumably due to pollution.

What happens to iron when it rusts?

When iron rusts, it weakens and can appear in different forms, like iron oxide.

What is the significance of the villi in the small intestine?

The height of the villi increases absorption efficiency due to more surface area for cells.

What condition might cause M
escents
Kenna
escents
s symptoms?

Possible conditions could involve malabsorption syndromes affecting nutrient uptake.

What defines a chemical change?

A chemical change is a process that involves rearrangement of the molecular or ionic structure of a substance, resulting in the formation of new substances.

What are some observable signs that a chemical change has taken place?

Common indicators include the production of gas (bubbles), formation of a precipitate, a change in color, a change in temperature, or the emission of light/heat.

What are the common units for density?

Density is commonly expressed in grams per cubic centimeter (g/cm^3) for solids and liquids, or grams per milliliter (g/mL) for liquids. Kilograms per cubic meter (kg/m^3) is also used.

What specific role do the cells lining the villi play in nutrient absorption?

The cells lining the villi contain enzymes for the final breakdown of carbohydrates and proteins, and actively absorb digested nutrients into the bloodstream or lymphatic system.

What is the density of water?

The density of water is approximately 1 \text{ g/cm}^3 or 1 \text{ g/mL}.

If an object has a density of 0.8 \text{ g/cm}^3, will it sink or float in water?

It will float because its density is less than water's density (1 \text{ g/cm}^3).

How does a physical change differ from a chemical change?

A physical change alters a substance's appearance but not its chemical composition, while a chemical change results in new substances with different properties.

What is iron oxide, and how is it related to rust?

Iron oxide is the chemical compound formed when iron rusts, commonly known as rust.

What specific type of pollution contributes to the deterioration of marble structures like the Taj Mahal?

Acid rain, which contains sulfuric acid (\text{H}2\text{SO}4) and nitric acid (\text{HNO}_3), reacts with the calcium carbonate in marble.

Besides villi, what other structures contribute to the increased surface area for absorption in the small intestine?

Plicae circulares (circular folds) and microvilli (on the surface of absorptive cells).

What is the primary role of microvilli in the small intestine?

Microvilli further increase the absorptive surface area and house enzymes for the final stages of digestion.

What are some general symptoms associated with malabsorption syndromes?

Common symptoms include chronic diarrhea, weight loss, bloating, and nutrient deficiencies.