There are two fewer electrons than protons, so the charge of the cation is 2. The symbol for this cation is Zn2. Changing the electrical charge of an atom usually has a major effect on its chemical properties. The two electrically neutral carbon isotopes should have nearly identical chemical properties; that is c.
Species with the same number of protons and electrons will be neutral. A, F, G. Species with more electrons than protons will have a negative charge. Species with more protons than electrons will have a positive charge.
Does this refer to hydrogen atoms or hydrogen molecules? One cannot be sure. NaCl is an ionic compound; it does not form molecules.
The law of multiple proportions requires that the masses of sulfur combining with phosphorus must be in the ratios of small whole numbers. For the three compounds shown, four phosphorus atoms combine with three, seven, and ten sulfur atoms, respectively.
If the atom ratios are in small whole number ratios, then the mass ratios must also be in small whole number ratios. Ionic compounds are typically formed between metallic especially Groups 1A, 2A, and aluminum and nonmetallic elements. Group 1A metals form M ions. Group 2A metals form Y2 ions. Aluminum forms an Al3 ion. Oxygen forms an O2 ion oxide. Nitrogen forms an N3 ion nitride , and the halogens form X ions. Making a table: Nonmetals.
The symbol 23Na provides more information than 11Na. The mass number plus the chemical symbol identifies a specific isotope of Na sodium , while combining the atomic number with the chemical symbol tells you nothing new. Can other isotopes of sodium have different atomic numbers? Cu, Ag, and Au are fairly chemically unreactive.
This makes them specifically suitable for making coins and jewelry, which you want to last a very long time. The following strategy can be used to convert from the volume of the Pt cube to the number of Pt atoms. The change in energy is equal to the energy released.
We call this E. Similarly, m is the change in mass. E Because m , we have c2 J 1. We can add together the masses of hydrogen and oxygen to calculate the mass of water that should be formed. Therefore, for all practical purposes, the law of conservation of mass is assumed to hold for ordinary chemical processes.
From the average magnitude of scattering, Rutherford estimated the number of protons based on electrostatic interactions in the nucleus. To calculate the density of the space occupied by the electrons, we need both the mass of 11 electrons and the volume occupied by these electrons.
The volume occupied by the electrons will be the difference between the volume of the atom and the volume of the nucleus.
The volume of the nucleus was calculated above. The volume of the atom is calculated as follows: pm. VelectronsVatomVnucleus 2. The density of the space occupied by the electrons can now be calculated.
Comparing the space occupied by the electrons to the volume of the nucleus, it is clear that most of the atom is empty space. Rutherford also proposed that the nucleus was a dense central core with most of the mass of the atom concentrated in it. The formula of the ionic compound is XY2. A possible compound is TiO2, titanium IV oxide. In the above two compounds, the ratio of atoms is the same. The diameter of a pea is about 0. Therefore, the expansion factor for the radius of the nucleus is 0.
Using that value as the distance of the electron from the. Eventually, rain leaches these compounds out of the soil and carries them to the sea. The acids, from left to right, are chloric acid, nitrous acid, hydrocyanic acid, and sulfuric acid.
The proton and neutron have approximately the same mass. Chemical properties change more markedly across a period. Strategy: The in Pu is the mass number. The mass number A is the total number of neutrons and protons present in the nucleus of an atom of an element. You can look up the atomic number number of protons on the periodic table.
Solution: mass number number of protons number of neutrons number of neutrons mass number number of protons 94 Elements can be grouped together according to their chemical and physical properties in a chart called the periodic table. The periodic table enables us to classify elements as metals, metalloids, and nonmetals and correlate their properties in a systematic way. Groups are the vertical columns of the periodic table, and periods are the horizontal rows of the table. Metals are good conductors of heat and electricity, while nonmetals are usually poor conductors of heat and electricity.
Metals, excluding mercury, are solids, whereas many nonmetals are gases. Column A is the alkali metals. Two examples are sodium Na and potassium K. Column B is the alkaline earth metals. Two examples are calcium Ca and barium Ba. Column C is the halogens. Two examples are fluorine F and iodine I. Column D is the noble gases. Two examples are argon Ar and xenon Xe. Helium and Selenium are nonmetals whose name ends with ium.
Tellerium is a metalloid whose name ends in ium. Metallic character increases as you progress down a group of the periodic table. For example, moving down Group 4A, the nonmetal carbon is at the top and the metal lead is at the bottom of the group. Metallic character decreases from the left side of the table where the metals are located to the right side of the table where the nonmetals are located. F and Cl are Group 7A elements; they should have similar chemical properties.
Na and K are both Group 1A elements; they should have similar chemical properties. P and N are both Group 5A elements; they should have similar chemical properties. An atom is the basic unit of an element that can enter into chemical combination.
A molecule is an aggregate of at least two atoms in a definite arrangement held together by chemical forces also called chemical bonds. Allotropes are two or more forms of the same element that differ significantly in chemical and physical properties. Diamond and graphite are allotropes of carbon.
Allotropes of an element differ in structure and properties, whereas isotopes of a given element contain different numbers of neutrons but have similar chemistries. This is a polyatomic molecule that is an elemental form of the substance. It is not a compound. This is a polyatomic molecule that is a compound. This is a diatomic molecule that is a compound. This is a polyatomic molecule that is the elemental form of the substance. You can find this on. The number of electrons in an ion is equal to the number of protons minus the charge on the ion.
Chemical formulas express the composition of molecules and ionic compounds in terms of chemical symbols. A molecular formula shows the exact number of atoms of each element in the smallest unit of a substance. An empirical formula shows the elements present and the simplest whole number ratio of the atoms but not necessarily the actual number of atoms in a given molecule.
P4 signifies one molecule that is composed of four P atoms. An ionic compound contains cations and anions. Electrical neutrality is maintained because the positive charge of the cations is balanced by the negative charge of the anions.
Ionic compounds do not consist of discrete molecular units but are three-dimensional networks of ions. The formula of ionic compounds represents the simplest ratio empirical formula in which the cation and anion combine.
Strategy: An empirical formula tells us which elements are present and the simplest whole number ratio of their atoms. Can you divide the subscripts in the formula by some factor to end up with smaller whole number subscripts? Dividing both subscripts by 2, the simplest whole number ratio of the atoms in Al 2Br6 is AlBr3.
The molecular formula as written, N2O5, contains the simplest whole number ratio of the atoms present. In this case, the molecular formula and the empirical formula are the same. The molecular formula as written, K2Cr2O7, contains the simplest whole number ratio of the atoms present. Ans: Answers will vary. Atoms are mostly empty space. The mass is concentrated mostly at the center of the atom. Category: Medium Section: 2. Use the periodic table above to show where the alkali metals are located.
Use the periodic table above to show where the alkaline earth metals are located. Use the periodic table above to show where the metals are located. Use the periodic table above to show where the metalloids are located. Use the periodic table above to show where the nonmetals are located.
Use the periodic table above to show where the halogen elements are located. Use the periodic table above to show where the noble gases are located. How many protons are there in one atom of nickel? Ans: 28 Category: Medium Section: 2. How many protons are there in one atom of magnesium? Ans: 12 Category: Medium Section: 2.
How many protons are there in one atom of xenon? Ans: 54 Category: Medium Section: 2. How many protons are there in one atom of uranium? Ans: 92 Category: Medium Section: 2. A molecule of antifreeze, ethylene glycol, has the formula C2H4 OH 2.
How many atoms are there in one molecule of antifreeze? Ans: 10 Category: Easy Section: 2. What is the total number of atomic particles protons, neutrons, and electrons in an atom of 3H? Ans: 4 Category: Medium Section: 2. What is the total number of atomic particles protons, neutrons, and electrons in an atom of 40Ca?
Ans: 60 Category: Medium Section: 2. What is the total number of atomic particles protons, neutrons, and electrons in an atom of 18F? Ans: 27 Category: Medium Section: 2. How many atoms are in one molecule of CaCl2? Ans: 3 Category: Easy Section: 2. How many atoms are in one molecule of C6H12O6? Ans: 24 Category: Easy Section: 2. Give the formula for potassium oxide. Give the formula for calcium chloride. Give the formula for carbon disulfide.
Give the formula for lithium hydroxide. Give the formula for nickel II sulfate. Name the following binary compound: FeS. Name the following binary compound: NaH. Ans: sodium hydride Category: Medium Section: 2. Name the following binary compound: MnCl2. Name the following binary compound: AgCl.
Ans: silver chloride; may accept silver I chloride. Name the following binary compound: Fe2O3. Name the following ternary compound: CuCO3. Name the following ternary compound: FeSO4. Name the following ternary compound: Na3PO4. Ans: sodium phosphate Category: Medium Section: 2. Name the following ternary compound: Al NO3 3. Ans: aluminum nitrate Category: Medium Section: 2. Name the following compound: Cl2O7.
Ans: dichlorine heptaoxide, or dichlorine heptoxide Category: Medium Section: 2. Name the straight chain hydrocarbon that contains eight carbon atoms. Ans: octane Category: Medium Section: 2. The table below describes four atoms. Consider a neutral atom of the following isotope of sulfur: 34 16 S How many electrons, protons, and neutrons does the atom contain? Ans: 16 electrons, 16 protons, and 18 neutrons Category: Medium Section: 2.
How many electrons, protons, and neutrons are in a neutral atom of the following isotope of calcium? How many electrons, protons, and neutrons are in a neutral atom of the following isotope of krypton? How many electrons, protons, and neutrons are in a neutral atom of the following isotope of gadolinium?
Write the names and symbols of two metals and two nonmetals. Identify which are the metals and which are the nonmetals. Metals: iron, Fe; sodium, Na; etc. Nonmetals: chlorine, Cl; nitrogen, N; etc. Predict the formula for the binary compound formed between potassium and sulfur. Predict the formula for the binary compound formed between aluminum and fluorine. Give the formula of magnesium nitrate. Give the formula of calcium phosphate. Give the formula of iron II phosphate.
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