Atoms, Elements And The Building Blocks Of Matter

Question 1

What are the 3 most important things on a periodic table block?

Answer 1

1) symbol
2) atomic number
3) molar mass

Question 2

What is the atomic number

Answer 2

The same number as the number of protons in the nucleus of an element, it is also the same number of electrons surrounding the nucleus of an element when its neutrally charged.

Question 3

How do you find the number of protons or electrons of an element on a periodic table?

Answer 3

Atomic number

Question 4

Which unit is used to measure atomic mass?

Answer 4

Atomic mass units

Question 5

What does the atomic mass represent?

Answer 5

The total mass of an atom.

Question 6

Define the molar mass of an element

Answer 6

The average mass for a mole of substance.

Question 7

What are the horizontal lines on a periodic table called?

Answer 7

Periods

Question 8

What are the vertical lines on a periodic table called?

Answer 8

Groups

Question 9

Label the names of groups on a periodic table

Question 10

How is the identity of an atom determined?

Answer 10

By the number of protons contained in it’s nucleus.

Question 11

What are isotopes?

Answer 11

Atoms of an element with different numbers of neutrons.

Question 12

How is the molar mass calculated?

Answer 12

The molar mass given on a periodic table is the average of the mass of all known isotopes weighted by their percent abundance

Question 13

Which technique can determine the mass of various Isotopes of an element?

Answer 13

Mass spectrometry

Question 14

Coefficients in chemical reactions tell you about the reactants & product in terms of?

Answer 14

Moles.

Question 15

What does avogadro’s number describe?

Answer 15

How many atoms are in a single mole of any given element.

Question 16

What is Avogadro’s number?

Answer 16

6.022x10^23

Question 17

Formula of moles

Answer 17

Moles = (particles/6.022x10^23)

Question 18

What can atomic mass signify?

Answer 18

How many grams are present in one mole of an element

Question 19

Which equation helps convert grams and moles?

Answer 19

Moles=grams/molar mass

Question 20

How do you calculate the number of moles of a gas?

Answer 20

Using the ideal gas equation.
PV=nRT
(n stands for moles of gas)

Question 21

How do you calculate the number of moles of a gas?

Answer 21

Moles = PV/RT
P= pressure (atm)
V= volume (L)
T= temperature (K)
R= the gas constant, 0.0821L*atm/mol*K

Question 22

What is the standard temperature pressure?

Answer 22

P= 1 atmosphere
T= 273 K
One mole of gas always occupies 22.4 L at stp

Question 23

How do you solve an equation with stp

Answer 23

Moles= L/(22.4L/mol)

Question 24

At stp how many liters does one mole of gas occupy?

Answer 24

22.4 L

Question 25

Define molarity:

Answer 25

Expresses the concentration of a solution in terms of volume

Question 26

How do you know if an equation is talking about molarity?

Answer 26

When you see a chemical symbol in brackets, like [Na^+] is the same as the concentration of molarity of sodium ions

Question 27

Formula to calculate molarity

Answer 27

M= moles of solute/ liters of solution

Question 28

What is percent composition?

Answer 28

The percent by mass of each element that makes up a compound

Question 29

How do you calculate molar mass?

Answer 29

Dividing the mass of each element or compound in a compound by the total molar mass for the substance.

Question 30

Calculate percent composition in each element of Ca(NO3)2