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3 years ago

Early people observed their surroundings and relied on...

Chemistry

2 answers:

Damm [24]3 years ago

6 0

Either instinct or observation

PolarNik [594]3 years ago

4 0

Each Other and the sun but now a days we relied on our phones

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Can someone please help me finish this all?

Phoenix [80]

Answer:2-liver because it doesnt belong to digestive system

3-esophagus because it doesnt belong to the circulatory system

4-heart because it doesnt belong to the nervous system

5-skull because it doesnt belong to the endocrine system

Explanation:

4 0

3 years ago

In the activity series, any metal on the list can be oxidized by the ions of elements_______it.

Aleonysh [2.5K]

Answer:

Below

Nitric acid

Lead

Sodium nitrate

Explanation:

The activity series is an arrangement of metals in order of decreasing reactivity. Metals that are higher up in the series displace metals that are lower in the series from dilute solutions. Hence, when the ion of a metal that is lower in the series reacts with a metal that is higher up in the series, the latter is oxidized.

Dilute acids dissolve metals above hydrogen in the activity series such as as zinc and lead. Platinum is much lower than sodium in the activity series hence platinum does not react with sodium nitrate.

3 0

3 years ago

PLEASE HELP!!!<br> How many km/hr are there in 6.01 x 10^6 yd/wk?

OlgaM077 [116]

Answer:

32.711

Explanation:

1 yard = 0.0009144 km

1 week = 168 hrs

6.01 x 10^6 / 168 = 35,773.81 yds/hr

= 32.711 km/hr

8 0

3 years ago

Entropy means that _________.A. the quantity of usable energy declines with each transformationB. energy can be neither created

son4ous [18]

Answer:

answer A

Explanation:

A) the quantity of usable energy declines with each transformation → True . Since the entropy increases , the amount of energy that can not be converted to useful energy increases and since the total amount of energy is conserved, the quantity of useful energy decreases.

B) energy can be neither created nor destroyed → False in the context of entropy , since the energy is conserved regardless of the changes in entropy (First law → conservation of energy vs second law → increase of entropy)

C) life should be impossible → False . Since the second law states that the entropy of the <u>universe </u>increases with time . Then the system (life) can experience a decrease in entropy at the expense of a larger increase in entropy of the surroundings ( so the net increase is positive)

D) it is not possible to observe an increase in molecular organisation → False . Same as C. A system can experience a decrease in entropy at the expense of a larger increase in entropy of the surroundings ( so the net increase is positive)

7 0

3 years ago

Solid NaI is slowly added to a solution that is 0.0079 M Cu+ and 0.0087 M Ag+.Which compound will begin to precipitate first?NaI

NeTakaya

Answer :

AgI should precipitate first.

The concentration of $Ag^+$ when CuI just begins to precipitate is, $6.64\times 10^{-7}M$

Percent of $Ag^+$ remains is, 0.0076 %

Explanation :

$K_{sp}$ for CuI is $1\times 10^{-12}$

$K_{sp}$ for AgI is $8.3\times 10^{-17}$

As we know that these two salts would both dissociate in the same way. So, we can say that as the Ksp value of AgI has a smaller than CuI then AgI should precipitate first.

Now we have to calculate the concentration of iodide ion.

The solubility equilibrium reaction will be:

$CuI\rightleftharpoons Cu^++I^-$