To find the mass of 1,000 protons in scientific notation, we first need to understand the value displayed by the calculator, which is \( 1.67 \times 10^{-21} \) grams. This value represents the mass of protons.
Since the displayed mass represents the mass of 1 proton in grams, we need to multiply this value by \( 1,000 \) to find the mass of \( 1,000 \) protons.
\[ \text{Mass of 1,000 protons} = 1,000 \times (1.67 \times 10^{-21}) \]
To perform the multiplication, we can rewrite \( 1,000 \) as \( 1.00 \times 10^{3} \):
\[ \text{Mass of 1,000 protons} = 1.00 \times 10^{3} \times 1.67 \times 10^{-21} \]
Now, we multiply the coefficients and add the exponents:
\[ 1.00 \times 1.67 = 1.67 \]
\[ 10^{3} \times 10^{-21} = 10^{3 - 21} = 10^{-18} \]
Now, combining these two results gives:
\[ \text{Mass of 1,000 protons} = 1.67 \times 10^{-18} \text{ grams} \]
Thus, the mass of \( 1,000 \) protons in scientific notation is:
\[ \boxed{1.67 \times 10^{-18}} \] grams.