An atom has 15 protons and 16 neutrons. What is its mass number?
What is 31
Elements in the same group have this in common.
What is same number of valence electrons?
What charge will a Group 2 element form?
What is +2?
Who first proposed the idea of “atomos”?
Who is Democritus?
How many valence electrons does oxygen have?
What is 2?
A substance made of only one type of atom is called this.
What is an element?
An atom has atomic number 20. How many electrons does it have (neutral)?
What is 20?
Why are noble gases unreactive?
What is full outer shell?
What charge will a Group 6 non-metal form?
What is −2?
What did J.J. Thomson discover?
What is the electron?
How many valence electrons does oxygen have?
What is 6?
A substance made of two or more different atoms chemically combined.
What is a compound?
An atom has mass number 39 and atomic number 19. How many neutrons?
What is 20?
Which type of elements are most likely to lose electrons?
What are metals?
Why do atoms form ions?
What is to get a full outer shell (become stable)?
What did Rutherford’s experiment prove about atoms?
What is mostly empty space with a dense nucleus?
How many total electrons does silicon have?
What is 14?
Sand in water is what type of mixture?
What is heterogeneous?
Why are atoms electrically neutral?
What is equal number of protons and electrons?
An element is shiny, ductile, and conducts electricity. What is it?
What is a metal?
What ion does aluminum (Al) form?
What is Al³⁺?
Why did Rutherford reject the plum pudding model?
What is because particles were deflected sharply?
How are valence electrons related to reactivity?
What is they determine how atoms bond/react?
Name one sign of a chemical change.
What is color change / gas formation / heat / odor?
An atom has 12 protons but 10 electrons. What is its charge?
What is +2 (cation)?
Where are metalloids located on the periodic table?
What is along the staircase (zig-zag line)?
An atom gains 2 electrons. What happens to its charge and type?
What is becomes −2, an anion?
Which model says electrons exist in probability clouds?
What is the quantum (electron cloud) model?
An atom has electron arrangement 2-8-1. What element is it?
What is sodium (Na)?
Why is freezing water a physical change?
What is no new substance is formed?