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?
11
12
22
44
Which of the following statements is not true?
Water is polar.
Water stabilizes temperature.
Water is essential for life.
Water is the most abundant molecule 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 ________.
fructose
glucose
galactose
all of the above
Cellulose and starch are examples of ________.
monosaccharides
disaccharides
lipids
polysaccharides
Phospholipids are important components of __________.
the plasma membrane of animal 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 _________.
nucleotides
disaccharides
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