Answer:
118.05 grams
Explanation:
mL = cm³
Density = mass/volume
Let x = mass
Our equation will look like this: x/15 = 7.87
Multiply both sides by 15 to isolate the variable, x
15(x/15) = 15(7.87)
15x/15 = 118.05
x = 118.05
It represents an observation and he formed a hypothesis to explain the observation.
Answer:
Pure substance: sugar
A chemical change: occurs when methane is burned.
Explanation:
Pure substances have definite <em>constant compositions</em> (reflected in formulas) and have their own <em>chemical properties</em>. On the other hand, mixtures are made of two or more pure substances (<em>variable composition</em>) and their chemical properties depend on each combination. From the list, only sugar is a pure substance (C₁₂H₂₂O₁₁), whereas seawater, air, lemonade, and milk are mixtures.
Chemical changes (chemical reactions) occur when pure substances transform into others, and therefore there are new formulas. Conversely, in physical changes, pure substances <em>preserve their identity</em> (formula) but have changes in their <em>physical properties</em>. Methane being burned is a chemical change since new substances are formed:
CH₄ + O₂ ⇄ CO₂ + H₂O
Water vaporization, paper shredding and dissolution of solids in liquids are examples of physical changes.
Answer:
Ba: 1s² 2s²2p⁶ 3s²3p⁶ 4s²3d¹⁰4p⁶ 5s²4d¹⁰5p⁶ 6s²
Step-by-step explanation:
Step 1. Locate barium in the Periodic Table.
It's in Period 6, Group 2: Element 56 (highlighted blue in the Periodic Table below).
Step 2. Add 54 electrons to the energy levels
You add then in the order shown in the diagram below.
The complete electron configuration is:
Ba: 1s² 2s²2p⁶ 3s²3p⁶ 4s²3d¹⁰4p⁶ 5s²4d¹⁰5p⁶ 6s²
n = 2 + 8 + 8 + 18 + 18 + 2 = 56
Answer:
A. Rutherford's discovery that atoms contain a nucleus
Explanation:
