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2 years ago

What new evidence led scientists to change their minds about the geocentric model?

1 answer:

3 0

Galileo disproved the Ptolemaic theory, sanctioned for centuries by the Church, which held the Earth to be the central and principal object in the universe, about which all celestial objects orbited.

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If an object has more positive charges than negative charges, the object has an overall?

guapka [62]

It will have an overall positive charge.

6 0

2 years ago

.325 mol KOH to grams

lesya [120]

The answer is 18.23432 grams.

Molar mass of KOH= 56.1056

$( \frac{1 mol}{56.1056 grams}) (\frac{.325 mol}{x grams})$ = 18.234 grams

5 0

2 years ago

A monoprotic weak acid when dissolved in water is 0.66% dissociated and produces a solution with a pH of 3.04. Calculate the Ka

raketka [301]

Answer:

Ka = 6.02x10⁻⁶

Explanation:

The equilibrium that takes place is:

HA ⇄ H⁺ + A⁻

Ka = [H⁺][A⁻]/[HA]

We calculate [H⁺] from the pH:

pH = -log[H⁺]

[H⁺] = $10^{-pH}$

[H⁺] = 9.12x10⁻⁴ M

Keep in mind that [H⁺]=[A⁻].

As for [HA], we know the acid is 0.66% dissociated, in other words:

[HA] * 0.66/100 = [H⁺]

We calculate [HA]:

[HA] = 0.138 M

Finally we calculate the Ka:

Ka = $\frac{[9.12x10^{-4}]*[9.12x10^{-4}]}{[0.138]}$ = 6.02x10⁻⁶

3 0

1 year ago

Nonmetals tend to boil at

Usimov [2.4K]

Answer:

D) Low temperatures

Explanation:

Non-metals are elements that do not show metallic characteristics like heat conductivity, electrical conductivity, malleability, e.t.c. They are generally less dense and are bonded with weak forces in between their compounds.

The weakness of non-metals is the chief reason why they generally tend to have low boiling point. Only the presence of impurities can cause an elevation in their boiling points.

Metals on the other hand are good heat conductors and they generally have a high boiling point.

7 0

2 years ago

Which indicator would tell scientists the most about future climate change

lara [203]

The data gotten from ice cores could scientists tell the about future climate change.

6 0

2 years ago