Chemical Rxns. & Genetics

In which of the following examples has a chemical reaction occurred?

• After putting liquid batter into a hot pan, the batter solidifies and begins to turn brown.

• After turning on a blender filled with different fruits, the fruit is chopped up and mixed.

• After taking a tray filled with ice cubes out of the freezer, the cubes begin to melt.

• After adding a spoonful of sugar to a mug of hot coffee, the sugar dissolves completely.

When vinegar and baking soda are combined, bubbles begin to form. Bubbles are evidence of a chemical reaction because they–

• pop when they are touched.

• show that a gas is forming.

• form at a fast rate.

• are generally transparent.

Which of the following equations is correctly balanced?

• A

• B

• C

• D

According to the law of conservation of mass–

• matter is always created in a chemical reaction.

• matter is always destroyed in a chemical reaction.

• matter is created and then destroyed in a chemical reaction.

• matter is not created or destroyed in a chemical reaction.

A student places a piece of a potato into a container of hydrogen peroxide. The student observes that bubbles form around the potato. The presence of bubbles might indicate the formation of a new substance because bubbles–

• could show that a gas is forming.

• always rise to the top of a liquid.

• are almost always perfectly spherical.

• usually burst after a few minutes.

A student notices that sugar heated over a flame turns black. How does the student know that a new substance is being formed?

• The sugar melts within the test tube.

• The temperature of the test tube increases.

• The color of the sugar changes to black.

• The mass of the sugar decreases.

In a ___________ change, a substance undergoes a change that results in new material created with different properties.

• Physical

• Chemical

True or False: Cutting a piece of paper is an example of a physical change

• True

• False

Which of the following describes heredity?

• A tiger teaching its young how to hunt

• A tree making food by photosynthesis

• Bacteria dividing into to make a new bacteria

• An animal eating a plant

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Who is considered the "father" of modern genetics?

• Einstein
• Mendel
• Disney
• Trump