A) -0.5(9.8)*t^2 = -25(t-2) - 0.5(9.8)(t-2)^2
-4.9t^2 = -25t + 50 - 4.9(t^2-4t+4)
0 = -25t+50+19.6t - 19.6
5.4t = 30.4
t = 5.62962963 s
b) h = -4.9(5.62962963)^2
h = -155.2943759
the building is 155.2943759 m high
c) speed 0of first stone
= at
= 9.8*5.62962963
= 55.17037037 m/s
speed of second stone
= v + at
= 25+9.8*3.62962963
= 60.57037037 m/s
You must verify that the number of atoms of each type is equal on both sides of the chemical equation: same number of C, same number of H and same number of O on both sides.
<span>A. C4H6 + 5.5O2 ---> 4CO2 + 3H2O
element reactant side product side
C 4 4
H 6 3*2 = 6
O 5.5 * 2 = 11 4*2 + 3 = 11
Then, this equation is balanced.
</span>Do the same with the other equations if you want to verify that they are not balanced.
Answer: option A.
Answer:
V₂ =279.9 cm³
Explanation:
Given data:
Initial volume = 360 cm³
Initial temperature = 50°C
Initial pressure = 700 mmHg
Final volume = ?
Final temperature = 273 k
Final pressure = 1 atm
Solution:
According to general gas equation:
P₁V₁/T₁ = P₂V₂/T₂
Solution:
<em>We will convert the mmHg to atm.</em>
700/760 = 0.92 atm
<em>and °C to kelvin.</em>
50+273 = 323 K
P₁V₁/T₁ = P₂V₂/T₂
V₂ = P₁V₁ T₂/ T₁ P₂
V₂ = 0.92 atm × 360 cm³ × 273 K / 323 K ×1 atm
V₂ = 290417.6 atm .cm³. K / 323 k. atm
V₂ =279.9 cm³
B - Atomic number. Dmitri Mendeleev organised the table according to atomic weight, however this caused problems with elements such as iodine and tellurium, Iodine has a higher mass, but a lower atomic number. And to make iodine in the same group as similar elements (halogens), Mendeleev had to break his own rules and put it before tellurium in the table. Moseley fixed this problem by ordering the elements according to atomic (proton) number.
<h3>
Answer:</h3>
28 mol CaF
<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Chemistry</u>
<u>Atomic Structure</u>
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
<u>Stoichiometry</u>
- Using Dimensional Analysis
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
[Given] 1.7 × 10²⁵ molecules CaF
[Solve] moles CaF
<u>Step 2: Identify Conversions</u>
Avogadro's Number
<u>Step 3: Convert</u>
- [DA] Set up:
- [DA] Multiply/Divide [Cancel out units]:
<u>Step 4: Check</u>
<em>Follow sig fig rules and round. We are given 2 sig figs.</em>
28.2298 mol CaF ≈ 28 mol CaF
