Unit 8 Flashcard B

Front

What does the pH indicator show when it changes color?

Back

The pH level of a solution.

Front

What is the mass number of an isotope with 22 protons and 18 neutrons?

Back

40

Front

What does it indicate if litmus paper turns red when dipped in a substance?

Back

The substance is acidic.

Front

In the symbol ⁹₄Be, what does the 9 represent?

Back

Mass number.

Front

What does it mean that ¹⁴₆C has a half-life of 25 days?

Back

It takes 25 days to decrease radioactivity by 50%.

Front

What is the definition of an isotope?

Back

Atoms of the same element with different numbers of neutrons.

Front

What is the atomic number of an element?

Back

The number of protons in the nucleus of an atom.

Front

How is the mass number calculated?

Back

By adding the number of protons and neutrons in an atom.

Front

What does a pH of less than 7 indicate?

Back

The solution is acidic.

Front

What does a pH of more than 7 indicate?

Back

The solution is basic.