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densk [106]
2 years ago
8

Help me with these questions.

Chemistry
1 answer:
Aloiza [94]2 years ago
5 0
1) C
2) B
3) A/B not sure
4) C I think

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Is H20 a balanced equation?
Nat2105 [25]

Answer:

no it's not

Explanation:

because H2+O2=H2O

so the balanced form is

H2 +O2=2H2O

8 0
3 years ago
HELP PLEASE ITS JUST MULTIPLE CHOICE
morpeh [17]

Answer:

Atoms are indivisible

I had a hard time finding this out.

Explanation: Dalton's atomic theory was the first complete attempt to describe all matter in terms of atoms and their properties. Dalton based his theory on the law of conservation of mass and the law of constant composition. The first part of his theory states that all matter is made of atoms, which are indivisible.

6 0
2 years ago
Vitamin D is produced in the skin when 7-dehydrocholesterol reacts with UVB rays (ultraviolet B) having wavelengths between
goblinko [34]

The energy range expected is 6.6 × 10^-19 J < E < 7.33 × 10^-19 J

The energy of the photon is given by;

E = hc/λ

E = energy of the photon

h = Plank's constant

c = speed of light

λ = wavelength of light

For the upper boundary range;

E = ?

h = 6.6 × 10^-34 Js

c = 3  × 10^8 m/s

λ = 270 × 10^-9

E =  6.6 × 10^-34 Js × 3  × 10^8 m/s / 270 × 10^-9

E = 7.33 × 10^-19 J

For the lower range;

E = ?

h = 6.6 × 10^-34 Js

c = 3  × 10^8 m/s

λ =300 × 10^-9

E =  6.6 × 10^-34 Js × 3  × 10^8 m/s / 300 × 10^-9

E = 6.6 × 10^-19 J

Hence, the energy range 6.6 × 10^-19 J < E <  7.33 × 10^-19 J

Learn more: brainly.com/question/24857760

8 0
2 years ago
Are watches considered as compound machines?
Alisiya [41]
Yes. They are called compound machines because two or more simple machines were combined to create it.
5 0
3 years ago
Three principal models of isostasy are used: 1. The Airy–Heiskanen model – where different topographic heights are accommodated
miss Akunina [59]

Answer:

the answer is B

Explanation:

8 0
2 years ago
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