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OlgaM077 [116]
2 years ago
6

True or False. Index Fossils are formed from organisms that were alive for short period of geologic time, are extinct, had hard

parts, and lived across wide geographic area.
Chemistry
2 answers:
NemiM [27]2 years ago
6 0

Answer:

Index fossil, any animal or plant preserved in the rock record of the Earth that is characteristic of a particular span of geologic time or environment.

Explanation:

True

erik [133]2 years ago
3 0

Answer:  

Explanation:

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In experiment 1, how many moles of benzoic acid are present? how many moles of sodium bicarbonate are contained in 1 ml of a 10%
nexus9112 [7]

First, let us calculate the moles of solute or sodium bicarbonate is in the 1 ml solution.

<span>moles  = 1 mL * (1 g / 9 mL) = 0.11 moles</span>

 

The molar mass of sodium bicarbonate is 84 g/mol, therefore the mass is:

mass = 0.11 moles * 84 g/mol

<span>mass = 9.33 g</span>

6 0
3 years ago
The second order reaction A → Products takes 13.5 s for the concentration of A to decrease from 0.740 M to 0.319 M. What is the
Ivanshal [37]

The rate constant of the second order reaction is 0.137 M-1s-1.

<h3>What is the rate constant?</h3>

For the second order reaction we can write;

1/[A] = kt + 1/[A]o

[A]o = initial concentration

[A] = final concentration

k = rate constant

t = time

Now;

1/0.319 = 13.5k + 1/ 0.740

1/0.319 - 1/0.740 = 13.5k

3.13 - 1.35 = 13k

k = 3.13 - 1.35/13

k = 0.137 M-1s-1

Learn more about second order reaction:brainly.com/question/12446045

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8 0
2 years ago
An aqueous solution is made by dissolving 26.4 grams of barium sulfide in 349 grams of water.
lukranit [14]

Answer:

Molality = 0.43 m

Explanation:

Given data:

Mass of barium sulfide = 25.4 g

Mass of water = 349 g (349 g/1000 = 0.349 Kg)

Molality of water = ?

Solution:

Number of moles of barium sulfide:

Number of moles = mass/molar mass

Number of moles = 25.4 g/169.39 g/mol

Number of moles = 0.15 mol

Molality:

Molality = number of moles o f solute/ Kg of solvent

Molality = 0.15 mol / 0.349 Kg

Molality = 0.43 m

4 0
3 years ago
The model represents a polynomial and its factors.
zepelin [54]

The equation that is represented by the model is = x²-2x-3=(x − 3)(x + 1).

<h3>What are polynomials?</h3>

Polynomials are defined as the mathematical expression that is made up of variables.and coefficients.

The model is +X-x-x- ,

Which is X -2x ( negative minus negative is plus)

Therefore, the equation that is represented by the model is = x²-2x-3=(x − 3)(x + 1)

Learn more about polynomials here:

brainly.com/question/2833285

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4 0
2 years ago
The atomic mass of an element depends upon the _____.
qwelly [4]

Answer: mass and relative abundance of each isotope of that element

Explanation:-

For example:

If an element X has two isotopes with following masses ad abundance:

Mass of isotope 1 = 267.8 amu

% abundance of isotope 1 = 87.8% = 0.878

Mass of isotope 2 = 269.9 amu

% abundance of isotope 2 = 12.2% = 0.122

Formula used for average atomic mass of an element :

\text{ Average atomic mass of an element}=\sum(\text{atomic mass of an isotopes}\times {{\text { fractional abundance}})

\text{ Average atomic mass of an element X}=\sum[(267.8\times 0.878)+(269.9\times 0.122)]

\text{ Average atomic mass of an element X}=268.06amu

8 0
2 years ago
Read 2 more answers
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