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3 years ago

A sample of matter must be copper if(1) each atom in the sample has 29 protons

1 answer:

3 0

<span>The answer is 1. Copper is an element with sign Cu and atomic number 29 which means that there are 29 protons in this element. It is a soft, flexible, and elastic metal with very extraordinary thermal and electrical conductivity. A newly unprotected exterior of pure copper has a reddish-orange color. </span>

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Can you guys please help me I will mark brainliest to whoever answers this right.

Sphinxa [80]

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7 0

3 years ago

250 ml of seawater and we inked each molecule with pink color, then we mixed this 250 ml in the ocean. After mixing you took 250

Marysya12 [62]

Answer:

9.77 × 10⁹ molecules

Explanation:

Since the density of water is 1 g/cm³ = 1000 g/L

So, we find the mass of sea water in 250 mL = 0.250 L

We know density = mass/volume

mass = density × volume = 1000 g/L × 0.250 L = 250 g

Now we calculate the number of moles of sea water in 250 g, 250 mL of sea water.

number of moles n = mass of sea water,m/molar mass of water, M

molar mass of water, M = 18 g/moL

n = m/M = 250 g/18 g/mol = 13.89 mol

We now calculate the number of molecules present in the 250 mL of sea water.

n = N/N' where N = number of molecules, N' = avogadro's number = 6.022 × 10²³/mol

So,N =nN' = 13.89 mol × 6.022 × 10²³/mol = 8.36 × 10²⁴ molecules

Now, the volume of the ocean is 1.337 × 10¹⁸ m³ = 1.337 × 10¹⁵ L

Since the 250 mL sea water is mixed with the ocean, the number of molecules per liter is 8.36 × 10²⁴ molecules/1.337 × 10¹⁵ L = 6.25 × 10⁹ molecules/L

If we now take 250 mL out of the ocean, the number of molecules in this 250 mL will be 6.25 × 10⁹ molecules/L × 250 mL = 6.25 × 10⁹ molecules/L × 0.250 L = 9.77 × 10⁹ molecules.

So, we have 9.77 × 10⁹ molecules of pink molecules in the 250 mL after mixing in the ocean.

6 0

3 years ago

How many elements are there

yawa3891 [41]

There are 118 known elements

4 0

4 years ago

Can someone please help me with this? This is due today, please please help me!

Elanso [62]

<h2>Hey There!</h2><h2>_____________________________________</h2><h2>Answer:</h2><h2>_____________________________________</h2>

ATOMIC NUMBER: It is the number of protons present in the nucleus of every atom

MASS NUMBER: It is the number of nucleon. Nucleon are the number of proton and neutrons present in the nucleus.

PROTON NUMBER: Proton number equal to the atomic number.

ELECTRON NUMBER: Electron Number is equal to the atomic number.

NEUTRON NUMBER: It is Mass Number - Atomic Number.

CHARGE: It is due to the addition or removal of the electron. + charge when electron removed and - charge when electron is added.

SYMBOL: It is represented as,

$X^Z_A$

Z is Mass Number

A is Atomic Number

<h2>_____________________________________</h2><h2>Worksheet:</h2>

(I) ATOMIC NUMBER: 17

MASS NUMBER: 35.5

PROTON NUMBER: 17

ELECTRON NUMBER: 17

NEUTRON NUMBER: 18.5

CHARGE: 0

(II) ATOMIC NUMBER: 71

MASS NUMBER: 180

PROTON NUMBER: 71

ELECTRON NUMBER: 71

NEUTRON NUMBER: 109

CHARGE: 0

(III) ATOMIC NUMBER: 40

MASS NUMBER: 86

PROTON NUMBER: 40

ELECTRON NUMBER: 38

NEUTRON NUMBER: 46

CHARGE: +2

(IV) ATOMIC NUMBER: 92

MASS NUMBER: 238

PROTON NUMBER: 92

ELECTRON NUMBER: 86

NEUTRON NUMBER: 146

CHARGE: +6

(V) ATOMIC NUMBER: 82

MASS NUMBER: 206

PROTON NUMBER: 82

ELECTRON NUMBER: 78

NEUTRON NUMBER: 124

CHARGE: +4

(VI) ATOMIC NUMBER: 34

MASS NUMBER: 79

PROTON NUMBER: 34

ELECTRON NUMBER: 36

NEUTRON NUMBER: 45

CHARGE: -2

(VII) ATOMIC NUMBER: 48

MASS NUMBER: 113

PROTON NUMBER: 48

ELECTRON NUMBER: 49

NEUTRON NUMBER: 65

CHARGE: -1

(VIII) ATOMIC NUMBER: 21

MASS NUMBER: 42

PROTON NUMBER: 21

ELECTRON NUMBER: 21

NEUTRON NUMBER: 21

CHARGE: 0

(IX) ATOMIC NUMBER:

MASS NUMBER:

PROTON NUMBER:

ELECTRON NUMBER:

NEUTRON NUMBER:

CHARGE:

(X) ATOMIC NUMBER: 83

MASS NUMBER: 209

PROTON NUMBER: 83

ELECTRON NUMBER: 80

NEUTRON NUMBER: 126

CHARGE: +3

(XI) ATOMIC NUMBER: 47

MASS NUMBER: 108

PROTON NUMBER: 47

ELECTRON NUMBER: 47

NEUTRON NUMBER: 61

CHARGE: 0

(XII) ATOMIC NUMBER: 49

MASS NUMBER: 116

PROTON NUMBER: 49

ELECTRON NUMBER: 46

NEUTRON NUMBER: 67

CHARGE: +3

(XIII) ATOMIC NUMBER: 53

MASS NUMBER: 128

PROTON NUMBER: 53

ELECTRON NUMBER: 54

NEUTRON NUMBER: 75

CHARGE: -1

(XIV) ATOMIC NUMBER: 76

MASS NUMBER: 188

PROTON NUMBER: 76

ELECTRON NUMBER: 72

NEUTRON NUMBER: 112

CHARGE: +4

<h2>_____________________________________</h2><h2>Best Regards,</h2><h2>'Borz'</h2><h2 />

4 0

3 years ago

A sample of sugar (C12H22O11) contains 1.505 × 1023 molecules of sugar. How many moles of sugar are present in the sample?

saveliy_v [14]

Answer: Option (a) is correct.

Explanation:

Molecules of sugar given = $1.505 \times 10^{23}$

According to Avogadro's number it is known that 1 mole contains $6.023 \times 10^{23}$ .

Therefore, calculate the moles of sugar present in the sample as follows.

Number of moles = $\frac {1.505 \times 10^{23}}{6.023 \times 10^{23}}$

= 0.25 mol

Thus, the moles of sugar present in the sample is 0.25 mol.

6 0

3 years ago

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