To find the mass of 1000 protons, we first need to understand what the display "1.6 7E -21" represents. It is likely in scientific notation.
The expression "1.67E-21" can be interpreted as:
\[ 1.67 \times 10^{-21} \]
But since we need to calculate the mass of 1000 protons, we should first determine the mass of a single proton. The mass of a single proton is approximately \(1.67 \times 10^{-27}\) grams.
Now, to find the mass of 1000 protons, we can multiply the mass of one proton by 1000:
\[ \text{Mass of 1000 protons} = 1000 \times (1.67 \times 10^{-27}) \]
Calculating this gives:
\[ 1000 \times 1.67 = 1670 \]
Thus, we have:
\[ \text{Mass of 1000 protons} = 1670 \times 10^{-27} \]
To express \(1670\) in scientific notation, we can write it as \(1.67 \times 10^{3}\). Therefore:
\[ 1670 \times 10^{-27} = 1.67 \times 10^{3} \times 10^{-27} = 1.67 \times 10^{-24} \]
So, the mass of 1000 protons in scientific notation is:
\[ \mathbf{1.67 \times 10^{-24}} \text{ grams} \]