Atoms: The Building Blocks of Matter

- Protons - Nuetrons - Electrons

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1- Masses of Fe (g) : 2- Masses if o (g): 3-Ratio of o:Fe

1- 55.85/111.70/167.55 2- 16.00/48.00/64.00 3- 0.2865/0.4297/0.3820

What is the mass in grams of 100 atoms of then carbon - 12 istopes?

1.993 x 10 (-21) g

How many atoms are in. 80.45g of magnesium?

1.994 X 10 24 atoms

If 3 g of element C combine with 8 g of element D to form compound CD, how many grams of D are needed to form compound CD2?

16g

1- Elements -' 2- Symbols 3- Atomic #- 4-Mass # - 5- Number of protons- 6-Number of neutrons- 7- Number of electrons-

1: Fluorine, Bromine, Calcium, Hydrogen , Radon 2: Na, Br, Ca, H, Rn 3: 11, 35, 20,86 4: 1 5:11, 9,35,1,86 6: 11, 10, 20, 136 7: 11, 9, 35, 20, 1

How many moles of aluminum exist in 100.0 g of aluminum?

3.706 mol

What is the mass in grams of 2.000 mol oxygen atoms?

32.00g

How did the outcome of Rutherford's gold-foiled experiment indicates the existence of a nucleus?

A few people alpha particles rebounded and therefore must have "hit" a dense bundle of matter. Because such a small percentage of particles were redirected, he reasoned that this clump of matter, called the nucleus, must occupy only a small fraction of the atom's total space.

Give an example of a chemical or physical process that illustrates the law of conservation of mass

A glass of ice cubes will have the same mass when the ice has completely melted into liquid water ,even though its volume will change.

Neutron

A nuclear particle that has no electrical charge charge is called

Protons

A positively charged particle found in the nucleus is called

A- (Students should place a -sign inside all circle) B- ( Students should place a + sign in the center and a - sign all circles)

A- before Rutherford's experiment B- after Rutherford's experiment

A. How many atoms are there in 2.50 mol of Hydrogen? B. How many atoms are there in 2.50 mol of uranium ? C. How many moles are present in 107 g of sodium?

A. 1.51 x 10 atoms B. 1.51 x 10 atoms C. 4.65 atoms

A. Is an atom positively charged , negatively charged , or neutral? B. Explain how an atom can exist in this state

A. Atoms are neutral B. Atoms consist of a positively charged nucleus, made up of protons and neutrons, that is surrounded by a negatively charged electron cloud. The positive and negative charged combine to form a neutral charge.

Explain what's happens to each of the following as the atomic masses of the elements in the periodic table table increases: A. Then number of protons B. The number of electrons C. The number af atoms in 1 mol of each element

A. Increase B. Increase C. Stays the same

Nitrogen and oxygen combine to form several compounds , as shown by the following table.

A. No- no2 = 2.0 / b. No2/no4= 2.0 / c. NO-No4= 4.0 D. Which law do these data illustrate The law of multiple proportions

A. Proton B. Neutron C. Electron ( a possible location of this particle)

A. The proton, a positive and relatively massive particle,should be located in the nucleus. B. The neutron, a neutral and relatively massive particle, should be located in the nucleus. C. The electron, a negative particle with a low mass, should be located in the cloud surrounding the nucleus.

State two (2) principles from Dalton's atomic theory that have been revived as new information has become available

Atoms are divisible into smaller particles called substomic particles. A given element can have atoms with different masses, called isotopes.

2H2+o2 2H2o

Atoms cannot be subdivided, created or destroyed . Also, atoms of different elements combine in simple,whole-number ratios to form compound.

Isotopes : 1 , 2 , 3 Mass : 19.99244 , 20.99395, 21.99138 Percent natural abundance : 90.51, 0.27, 9.22 Mass number : 20 , 21, 22

Calculate the average atomic mass of this element : 20 amu

Why is Democritu's view of matter considered only idea , while Dalton's view is considered a theory ?

Democritus's idea of matter does not relate atoms to a measurable property, while Dalton's theory can be tested through quantitative experimentation.

Why is it necessary to use the average atomic mass of all istopes , rather than the mass of the mass of the most commonly occurring istopes , when referring to the atomic mass of an element?

Elements rarely occur as only one istopes, rather, they exist as mixtures of different istopes of various masses. Using a weighted average atomic mass, you can account for less common istopes.

Cathode

In cathode - ray tubes , the cathode ray is emitted from the negative electrode,which is called the

Explain the difference between the mass number and the atomic number of a nuclide.

Mass number is the total number of protons and neutrons in the nucleus of isotope.Atomic number is the total number of protons in the nucleus of each atom of an element.

How would the electrons produced in a cathode- ray tube filled with neon gas compare with the electrons produced in a cathode - ray tube filled with chlorine gas?

The electrons produced from neon gas and chlorine gas would behave in the same way because electrons do not differ from element to element.

Ibuprofen C13H18O2 that is manufactured in Michigan contains 75.69% by mass carbon, 8.80% hydrogen , and 15.51% oxygen . If you buy some ibuprofen for a headache while you are on vacation in Germany , how do you know that it has the same percentage composition as the ibuprofen you buy at home?

The law of definite proportions states that a chemical compound contains the same elements in exactly the same proportions by mass regardless of the site of the sample or the source of the compound.

A cathode ray produced in a gas-filled tube is defected by a magnetic field. A wire carrying an electric current can be pulled by a magnetic field. A cathode ray is deflected away from a negatively charged object. What property of the cathode ray shown by these phenomena?

The particles that compose cathode rays are negatively charged.

The element. Boron B , has an atomic mass 10.81 amu according to the periodic table. However , no single atom of boron has a mass of exactly 10.81 amu. How can you explain this difference?

The periodic table reports the average atomic mass , which is a weighted average of all istopes of bacon.

Atom

The smallest unit of element that can exist either alone or in molecules containing the same or different elements is

Electron and neutrons

The substomic particles that are least massive and most massive , respectively, are the

How many particles are in 1 mol of carbon? 1 mol of carbon? 1 mol of eggs ? Will 1 mol of each of these substance have the same mass?

There are 6.022 x 10 particles in 1 mol each of these substances. One mole of one substance will not necessarily have the same mass as one mole of another substance.

A sampled of baking soda, NaHCO3, always contains 27.37% by mass of sodium , 1.20% of hydrogen, 14.30% of carbon and 57.14% of oxygen

a. Which law do these data illustrate The law of definite proportions B. State the law A chemical compound contains the same elements in exactly the same proportions by mass regardless of the sample or the source of the compound