Category 1 STAAR SET
Based on its chemical formula, which of the following substances is not an organic compound?
. Ammonium SULFIDE, (NH₄)₂S
The chemical formula for sodium sulfate is Na₂SO₄. How many sodium atoms are in the formula?
2
How many atoms in all in a molecule of serotonin? C₁₀H₁₂N₂O
25
What is the mass number of a potassium (K) atom that has 20 neutrons?f
39
The chemical formula for sodium sulfate is Na₂SO₄. How many Oxygen atoms are in the formula?
4
Ca+ CaO
One element and one compound
What atom has 37 protons and 1 valence electron?
Rubidium (Rb)
The atoms of a certain element each contain 36 protons and 8 valence electrons. Which statement correctly identifies this element and describes its chemical reactivity?
The element is Krypton, it is a noble gas, thus not reactive.
The atoms of a certain element each contain 11 protons and 1 valence electron. Which statement correctly identifies this element and describes its chemical reactivity?
The element is sodium, it is highly reactive.
CaCO₃→CaO + CO₂ In the chemical reaction above, the products are best classified as :
Two compounds
Based on its chemical formula, which of the following substances is an organic compound?
Urea, CH₄N₂O
Carbon
What element is this?
