The radius of a hydrogen atom is 0.0000000529177 of a millimeter. Express this number as an approximation.(1 point)
Responses
(a) 0.00000005
0.00000005
(b) 0.0000000053
0.0000000053
(c) 0.0000005
0.0000005
(d) 0.00000006
The correct approximation is (a) 0.00000005.
How many times is 4 × 104 larger than 2 × 102 ?(1 point)
Responses
2,000
2,000
2
2
20
20
200
To calculate how many times 4 × 10^4 is larger than 2 × 10^2, we can simplify the expression:
4 × 10^4 / (2 × 10^2) = (4/2) × (10^4 / 10^2) = 2 × 10^2
Therefore, 4 × 10^4 is 200 times larger than 2 × 10^2.
The correct response is (d) 200.
At the end of fiscal year 2004, the federal debt of Country C is $278,560,125,000. What is the closest estimation of this amount? Express your answer in the form of a single digit times an integer power of 10.(1 point)
Responses
3 × 1011
3 times 10 superscript 11 baseline
2 × 1011
2 times 10 superscript 11 baseline
3 × 10−11
3 times 10 superscript negative 11 baseline
2.79 × 1011
The closest estimation of the federal debt of Country C at the end of fiscal year 2004, $278,560,125,000, is 2.79 × 10^11.
The correct response is (d) 2.79 × 10^11.
How many times less is 102 than 106 ? Express your answer as an integer power of 10.(1 point)
Responses
0.0001
0.0001
10−4
10 superscript negative 4 baseline
104
10 superscript 4 baseline
10,000
To determine how many times less 10^2 is than 10^6, we can calculate:
10^6 / 10^2 = 10^(6-2) = 10^4
Therefore, 10^2 is 10^4 times less than 10^6.
The correct response is (c) 10^4.
Question
Roughly, it takes light less than 0.000000003 of a second to travel a one-meter distance. Express this number in the form of a × 10n where 1 < a < 10 and is a one-digit number.(1 point)
Responses
3 × 109
3 times 10 superscript 9 baseline
3 × 108
3 times 10 superscript 8 baseline
3 × 10−8
3 times 10 superscript negative 8 baseline
3 × 10−9
To express the number in the form of a × 10^n, where 1 < a < 10 and is a one-digit number, we can represent 0.000000003 as 3 × 10^(-9).
Therefore, the correct response is (d) 3 × 10^(-9).
Neutrons are blue
Protons are red
Electrons are green
Which of the following do you need to add to complete this model of a neutral Beryllium (Be) atom? Choose all that apply. (Hint: Make sure to check how many particles are already in the model.)
(2 points)
Responses
1 more proton
1 more proton
2 more neutrons
2 more neutrons
3 more electrons
3 more electrons
2 more electrons
2 more electrons
1 more neutron
To complete a model of a neutral Beryllium (Be) atom, we need to consider the atomic number and atomic mass of Beryllium.
Beryllium (Be) has an atomic number of 4, which means it has 4 protons. Since the model already includes protons, we do not need to add any more protons.
Beryllium (Be) also has an atomic mass of 9.0122 atomic mass units (amu). Atomic mass is the sum of protons and neutrons in an atom. If the model already has the appropriate number of protons, we need to add the necessary number of neutrons to match the atomic mass.
Therefore, we need to add 5 - 4 = 1 more neutron to complete the model of a neutral Beryllium (Be) atom.
The correct response is (e) 1 more neutron.