Which of the following substances is an element?(1 point)

Question

Responses

salt
salt

protein
protein

insulin
insulin

hydrogen

Answer 1

The substance that is an element is hydrogen.

Answer 2

Which of these properties is a chemical property?(1 point)
Responses

flammability
flammability

hardness
hardness

magnetism
magnetism

melting point

Answer 3

The property that is a chemical property is flammability.

Answer 4

The chemical formula for methane is CH 4
. What is the fixed ratio of carbon (C) to hydrogen (H)?(1 point)
Responses

4:5
4:5

1:5
1:5

1:4
1:4

1:1

Answer 5

The fixed ratio of carbon (C) to hydrogen (H) in methane (CH₄) is 1:4.

Answer 6

Kendra finds the dimensions of a sticky note. She uses a meter stick to determine that the dimensions are 1.25×10−8 meters wide by 2.5×10−6 meters long. Use scientific notation to write the dimensions in millimeters.

Note: 1 meter is equal to 1,000 millimeters.

(1 point)
Responses

1.25×10−10 by 2.5×10−8 millimeters
1.25 times 10 superscript negative 10 baseline by 2.5 times 10 superscript negative 8 baseline millimeters

1.25×10−5 by 2.5×10−3 millimeters
1.25 times 10 superscript negative 5 baseline by 2.5 times 10 negative cubed millimeters

1.25×10−11 by 2.5×10−9 millimeters
1.25 times 10 superscript negative 11 baseline by 2.5 times 10 superscript negative 9 baseline millimeters

1.25×10−6 by 2.5×10−4 millimeters

Answer 7

To convert the dimensions of the sticky note from meters to millimeters, you need to multiply the measurements in meters by 1,000 (since 1 meter = 1,000 millimeters).

1. Width:
   \( 1.25 \times 10^{-8} \text{ meters} \times 1,000 = 1.25 \times 10^{-8} \times 10^3 = 1.25 \times 10^{-5} \text{ millimeters} \)

2. Length:
   \( 2.5 \times 10^{-6} \text{ meters} \times 1,000 = 2.5 \times 10^{-6} \times 10^3 = 2.5 \times 10^{-3} \text{ millimeters} \)

Therefore, the dimensions in millimeters are:

1.25×10−5 by 2.5×10−3 millimeters.