Magnesium has an atomic number of 12. Which of the following statements is true of a neutral magnesium atom?
- It has 12 protons, 12 electrons, and 12 neutrons.
- It has 12 protons, 12 electrons, and six neutrons.
- It has six protons, six electrons, and no neutrons.
- It has six protons, six electrons, and six neutrons.
Which type of bond represents a weak chemical bond?
- hydrogen bond
- ionic bond
- covalent bond
- polar covalent bond
An isotope of sodium (Na) has a mass number of 22. How many neutrons does it have?
Which of the following statements is not true?
- Water is polar.
- Water stabilizes temperature.
- Water is essential for life.
- Water is the most abundant atom in Earth’s atmosphere.
Using a pH meter, you find the pH of an unknown solution to be 8.0. How would you describe this solution?
- weakly acidic
- strongly acidic
- weakly basic
- strongly basic
The pH of lemon juice is about 2.0, whereas tomato juice's pH is about 4.0. Approximately how much of an increase in hydrogen ion concentration is there between tomato juice and lemon juice?
- 2 times
- 10 times
- 100 times
- 1000 times
An example of a monosaccharide is ________.
- all of the above
Cellulose and starch are examples of ________.
Phospholipids are important components of __________.
- the plasma membrane of cells
- the ring structure of steroids
- the waxy covering on leaves
- the double bond in hydrocarbon chains
The monomers that make up proteins are called _________.
- amino acids