Which number is correctly written in scientific notation?(1 point)

2.520 × 10^3

The age of Earth is about 4.6×109

years old. What is the number in decimal notation?(1 point)

4,600,000,000

Use scientific notation to compare these numbers: 3,478,660; 34,870,000; and 34,786,600. Which number has the greatest value?(1 point)

To compare the numbers using scientific notation, we need to convert them to the same power of 10.

3,478,660 = 3.47866 × 10^6
34,870,000 = 3.487 × 10^7
34,786,600 = 3.47866 × 10^7

Comparing the coefficients, we see that 3.487 × 10^7 is the greatest value.

Question

The density of oxygen is about 1.429 × 10−4
grams per liter. Which number is higher than 1.429 × 10−4
?(1 point)

To determine which number is higher than 1.429 × 10^-4, we need to compare the coefficients of the numbers:

1.429 × 10^-4 (original number)
0.001 (1 x 10^-3) (higher number)

Comparing the coefficients, we see that 0.001 (1 x 10^-3) is higher than 1.429 × 10^-4.

Convert 8.0724×10−12

centimeters to kilometers. Express the answer to the exact decimal place.

Note: 1 kilometer is equal to 100,000 centimeters.

To convert 8.0724 × 10^-12 centimeters to kilometers, divide by 100,000:

8.0724 × 10^-12 cm = 8.0724 × 10^-17 km

So, the answer, expressed to the exact decimal place, is 8.0724 × 10^-17 kilometers.

Linda converted 0.0005 liters to milliliters using a calculator. The calculator displayed the number 5E−7

. What is this number in scientific notation?(1 point)

The number 5E-7 is already in scientific notation. In expanded form, it would be 5 × 10^-7.

Which expression is equal to 5.1×10−3

?(1 point)

The expression that is equal to 5.1 × 10^-3 is:

0.0051

wrong

Apologies for the incorrect response.

The expression that is equal to 5.1 × 10^-3 is:

0.0051

Which expression is equal to 5.1×10−3

?(1 point)
Responses

3.9×10^−3+1.2×10^−3
2.9×10^−3+1.2×10^−3
2.2×10^−1+2.9×10^−2
3.5×10^3+1.6×10^−6

The expression that is equal to 5.1 × 10^-3 is:

2.9 × 10^-3 + 2.2 × 10^-3

Denali, which is about 20,000 ft. above sea level, is the highest mountain in the United States. Mt. Everest, the highest mountain on earth, is about 9×103

ft. higher than Denali. About how high is Mt. Everest? The answer should be in scientific notation.(1 point)

To find the height of Mt. Everest, we need to add the difference in elevation to the height of Denali.

Denali: 20,000 ft = 2 × 10^4 ft

Mt. Everest: 9 × 10^3 ft higher than Denali

Adding the two values, we get:

2 × 10^4 ft + 9 × 10^3 ft = 2.9 × 10^4 ft

Therefore, Mt. Everest is approximately 2.9 × 10^4 ft in height.

In 1500 CE, the world’s population was about 4.5×108

. In 2020, the world’s population was about 7.8×109
. Find how much the world’s population increased. (1 point)

To find the increase in the world's population from 1500 CE to 2020, we need to subtract the population in 1500 from the population in 2020.

Population in 1500 CE: 4.5 × 10^8
Population in 2020: 7.8 × 10^9

Increase in population: (7.8 × 10^9) - (4.5 × 10^8)

To subtract these values, we need to align the exponents:

7.8 × 10^9 - 0.45 × 10^10

Now, subtracting the coefficients, we get:

7.8 - 0.45 = 7.35

Therefore, the world's population increased by approximately 7.35 × 10^9 from 1500 CE to 2020.

In 2010, approximately 4.6×107

tons of paper were recycled. In the same year, an estimated 2,600,000 tons of plastics were recycled. How many more tons of paper was recycled than plastic in 2010?(1 point)

To find out how many more tons of paper were recycled than plastic in 2010, we need to subtract the amount of recycled plastic from the amount of recycled paper.

Recycled paper: 4.6 × 10^7 tons
Recycled plastic: 2,600,000 tons

To align the units, we need to convert the recycled plastic to scientific notation:

Recycled plastic: 2.6 × 10^6 tons

Now we can subtract the values:

4.6 × 10^7 tons - 2.6 × 10^6 tons

To subtract these values, we need to align the exponents:

46 × 10^6 tons - 2.6 × 10^6 tons

Now, subtracting the coefficients, we get:

46 - 2.6 = 43.4

Therefore, there were approximately 43.4 million more tons of paper recycled than plastic in 2010.

There are about 6×1019

atoms in a grain of sand. A cubic foot of sand can hold about 4×109
grains of sand of average size. Using those figures, how many atoms would you expect to find in a cubic foot of sand? Write the answer in scientific notation.(1 point)

To find the number of atoms in a cubic foot of sand, we need to multiply the number of atoms in a single grain of sand by the number of grains in a cubic foot.

Number of atoms in a grain of sand: 6 × 10^19 atoms
Number of grains of sand in a cubic foot: 4 × 10^9 grains

To calculate the number of atoms, we multiply these values:

6 × 10^19 atoms/grain * 4 × 10^9 grains/ft^3

Multiplying the coefficients and adding the exponents, we get:

6 * 4 × 10^19 * 10^9 = 24 × 10^28

We can simplify this to:

2.4 × 10^29

Therefore, you would expect to find approximately 2.4 × 10^29 atoms in a cubic foot of sand.