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3 years ago

Pls help me with this atomic number worksheet I will make you the brainiest worth 25 points

Chemistry

1 answer:

ELEN [110]3 years ago

7 0

Answer:

HELLO THERE!

I HOPE MY ANSWER WILL HELP YOU :)

Explanation:

PLEASE NOTE; I HAVE WRITTEN THE ATOMIC NUMBER IN BRACKETS, NEXT TO THE SYMBOL OF THE ELEMENT

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There are different atoms and each type of atom is called an

Brut [27]

Atoms are made up of protons , electrons and neutrons ..,, Atoms of the same element with different number of neutrons are called isotopes. Saying that substance “contains only one type of atom “ really means that it contains only atoms that all have the same number of protons .

3 0

3 years ago

Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolat

ad-work [718]

Answer:

The correct answer is 0.00582 grams.

Explanation:

In order to solve the question, let us consider the vapor pressure of H2O, as hydrogen gas is collected over water, therefore, we have to consider the vapor pressure of water in the given case. Let us assume that the pressure is 760 torr or 1 atm.

It is known that the vapor pressure of water at 40 degree C is 53.365 torr (Based on the data).

Therefore, the pressure of H2 will be,

P = 760-55.365 = 704.635 torr or 704.635/760 = 0.9272 atm

The volume of the hydrogen gas collected in the tube is 80 ml or 0.08 L

Temperature in Kelvin will be 40+273 = 313 K

To calculate the moles of hydrogen (H2) gas, there is a need to use the ideal gas equation, that is, PV= nRT, in this R is the gas constant, whose value is 0.0821 L atm/molK, and n is the moles of the gas.

By inserting the values in the equation we get:

PV = nRT

n = PV/RT = 0.9272 *0.08 / 0.0821 * 313

n = 0.00289 moles

The mass of H2 will be moles * molar mass = 0.00289 * 2.016

= 0.00582 grams.

7 0

3 years ago

A 0.539 g sample of a metal, M, reacts completely with sulfuric acid according to the reaction M(s)+H2SO4(aq)⟶MSO4(aq)+H2(g) A v

Charra [1.4K]

Answer:

The molar mass of the metal is 54.9 g/mol.

Explanation:

When we work with gases collected over water, the total pressure (atmospheric pressure) is equal to the sum of the vapor pressure of water and the pressure of the gas.

Patm = Pwater + PH₂

PH₂ = Patm - Pwater = 1.0079 bar - 0.03167 bar = 0.9762 bar

The pressure of H₂ is:

$0.9762bar.\frac{1atm}{1.013bar} =0.9637atm$

The absolute temperature is:

K = °C + 273 = 25°C + 273 = 298 K

We can calculate the moles of H₂ using the ideal gas equation.

$P.V=n.R.T\\n=\frac{P.V}{R.T} =\frac{0.9637atm \times 0.249L }{(0.08206atm.L/mol.K)\times298K} =9.81 \times 10^{-3} mol$

Let's consider the following balanced equation.

M(s) + H₂SO₄(aq) ⟶ MSO₄(aq) + H₂(g)

The molar ratio of M:H₂ is 1:1. So, 9.81 × 10⁻³ moles of M reacted. The molar mass of the metal is:

$\frac{0.539g}{9.81 \times 10^{-3} mol} =54.9g/mol$

4 0

3 years ago

How does a scientist explain something when a controlled experiment cannot be carried out

Romashka [77]

<span> We look for evidence. There are numerous natural phenomenon that we can't observe happening in real-time because they happen over large time scales, or large spatial scales. But we can observe the effects of these phenomenon and make predictions about what other effects we should see. </span>

7 0

3 years ago

Which nuclide is most likely to be radioactive and synthetic

White raven [17]

Answer:

237/93 np

Explanation:

sub to tkwick

7 0

2 years ago