What are all the elements to the left of the zigzag line in a periodic table called?

How are hypotheses different from theories?

juin [17]

Answer:

Explanation:

This is the Difference Between a Hypothesis and a Theory. In scientific reasoning, a hypothesis is an assumption made before any research has been completed for the sake of testing. A theory on the other hand is a principle set to explain phenomena already supported by data.

4 0

3 years ago

The diameter of the He He atom is approximately 0.10 nm nm . Calculate the density of the He atom in g/cm 3 g/cm3 (assuming that

Sladkaya [172]

Answer:

Density of the He atom = 12.69 g/cm³

Explanation:

From the information given:

Since 1 mole of an atom = 6.022x 10²³ atoms)

1 atom of He = $1 \ atom \times (\dfrac{1 \ mole}{ 6.022 \times 10^{23} \ atoms}) \times ( \dfrac{4.003 \ grams}{ 1 \ mole})$

$=6.647 \times 10^{-24} \ grams$

The volume can be determined as folows:

since the diameter of the He atom is approximately 0.10 nm

the radius of the He = $\dfrac{0.10}{2}$ = 0.05 nm

Converting it into cm, we have:

$0.05 nm \times \dfrac{10^{-9} \ meters}{ 1 nm} \times \dfrac{ 1 cm }{10^{-2} \ meters}$

$=5 \times 10^{-9} \ cm$

Assuming that it is a sphere, the volume of a sphere is

= $\dfrac{4}{3}\pi r^3$

= $\dfrac{4}{3}\pi \times (5\times 10^{-9})^3$

= $5.236 \times 10^{-25} \ cm^3$

Finally, the density can be calcuated by using the formula :

$Density = \dfrac{mass}{volume}$

$D = \dfrac{6.647 \times 10^{-24} \ grams }{ 5.236 \times 10^{-25} \ cm^3}$

D = 12.69 g/cm³

Density of the He atom = 12.69 g/cm³

4 0

3 years ago

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What does temperature indirectly measure? 1)Sound 2)Thermometers 3)Chemical Reactions 4)Heat

attashe74 [19]

Answer:

Heat

Explanation:

Temperature is the average thermal energy (or heat) in a substance. Sound isn't really related, thermometers measure temperature, and chemical reactions can produce heat, but none of those are measured by temperature.

3 0

2 years ago

1 point

monitta

Answer: C) a redox reaction that produces an electric current

Explanation:

Chemical cell is a device which is used for the conversion of the chemical energy produced in a redox reaction into the electrical energy. The cell consists of the negative terminal called as anode where oxidation takes place and a positive terminal called as cathode where reduction takes place.

Electrolytic cell is a device which is used to carry out chemical reactions by the use of electrical energy. The cell consists of the negative terminal called as cathode where reduction takes place and a positive terminal called as anode where oxidation takes place.

7 0

3 years ago

Coal _____.

butalik [34]

Produces almost half of out nation's electricity

6 0

3 years ago

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