13. Which of the following correctly provides the names and formulas of polyatomic ions?

The engineering process defines the steps engineers take to create

kupik [55]

Answer:

A.

Explanation:

Common sense<3

5 0

2 years ago

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Write isotopic symbols in the form AZX for each isotope. a. the copper isotope with 34 neutrons b. the copper isotope with 36 ne

krek1111 [17]

Explanation:

The form AZX denoted that;

Z = The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element.

A = Mass Number ( Sum of Neutrons and Protons)

X represents the element.

A. the copper isotope with 34 neutrons

X = Cu

Atomic Number of Copper, Z = 29

Mass Number, A = 29 + 34 = 63

63.29.Cu

B. the copper isotope with 36 neutrons

X = Cu

Atomic Number of Copper, Z = 29

Mass Number, A = 29 + 36 = 65

65.29.Cu

C. the potassium isotope with 21 neutrons

X = K

Atomic Number of Potassium, Z = 19

Mass Number, A = 19 + 21 = 40

40.19.K

D. the argon isotope with 22 neutrons

X = Ar

Atomic Number of Argon, Z = 18

Mass Number, A = 18 + 22 = 40

40.18.Ar

5 0

2 years ago

How many moles are in 2.98x10^23 particles?

Novosadov [1.4K]

Answer:

$\boxed {\boxed {\sf 0.495 \ mol}}$

Explanation:

We are given a number of particles and asked to convert to moles.

<h3>1. Convert Particles to Moles </h3>

1 mole of any substance contains the same number of particles (atoms, molecules, formula units) : 6.022 *10²³ or Avogadro's Number. For this question, the particles are not specified.

So, we know that 1 mole of this substance contains 6.022 *10²³ particles. Let's set up a ratio.

$\frac { 1 \ mol }{6.022*10^{23 } \ particles}}$

We are converting 2.98*10²³ particles to moles, so we multiply the ratio by that value.

$2.98*10^{23} \ particles *\frac { 1 \ mol }{6.022*10^{23 } \ particles}}$

The units of particles cancel.

$2.98*10^{23} *\frac { 1 \ mol }{6.022*10^{23 } }}$

$\frac { 2.98*10^{23}}{6.022*10^{23 } }} \ mol$

$0.4948522086 \ mol$

<h3>2. Round</h3>

The original measurement of particles (2.98*10²³) has 3 significant figures, so our answer must have the same.

For the number we found, 3 sig figs is the thousandth place.

The 8 in the ten-thousandth place (0.4948522086) tells us to round the 4 up to a 5 in the thousandth place.

$0.495 \ mol$

2.98*10²³ particles are equal to approximately <u>0.495 moles.</u>

3 0

2 years ago

PLEASE HELPPP :[

kkurt [141]

Answer:

C. The fruit and the hamburgers were affected by an increase in heat energy.

Explanation:

One claim Harvey can use to support the examples from his experiment is that the hamburgers and fruits were affected by an increase in the heat energy.

This chemical change is one that is solely driven.
This action Harvey is carrying out is cooking
When meals are cooked, the raw substances undergoes chemical change via the action of heat.

5 0

1 year ago

A hypothesis is a statement that can be tested through a scientific investigation. What is the purpose of writing a hypothesis?

netineya [11]

Answer: The purpose of a hypothesis is to find the answer to a question.

Explanation:

A hypothesis is a statement which is written as a source of prediction which is based upon the assumption of the cause of a natural event or process. The purpose of the hypothesis is basically to find the relevant answers to the scientific question. It is based upon few evidences and the entire statement of the hypothesis is tested using experimental procedures.

6 0

2 years ago

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