Question

An atomic model shows 19 protons, 20 neutrons, and 19 electrons. What is the mass number of the atom?

A = 39

B = 58

C = 20

D = 19

Answer 1

To create a molecular model, a student will use blue spheres to represent nitrogen (N) and white spheres to represent hydrogen (H). Which option correctly describes a model of ammonia, NH³?

A = one blue sphere and one white sphere

B = three blue spheres and one white sphere

C = three blue spheres and three white spheres

D = one blue sphere and three white spheres

Answer 2

A ball-and-stick model of a molecule of formaldehyde, CH²O, is made from the following components:

• one black ball
• one red ball
• two white balls
• three sticks

What do the sticks represent?

A= carbon atoms

B= hydrogen atoms

C= bonds between atoms

D= oxygen atoms

Answer 3

Use the equation below to answer the question.

baking soda + vinegar = carbon dioxide + water + sodium acetate

which are the products in this equation?

A= sodium acetate only

B= baking soda, vinegar, carbon dioxide, water, and sodium acetate

C= baking soda and vinegar

D= carbon dioxide, and sodium acetate