Matter & Changes
This state of matter has a definite shape and volume.
What is a solid?
This type of mixture has the same appearance and composition throughout.
What is homogeneous?
He proposed the first atomic theory that described atoms as indivisible spheres.
Who is John Dalton?
If the atomic mass is 12.01, what would the mass number be?
What is 12?
These particles are found inside the nucleus.
What are protons and neutrons?
This type of radiation can be stopped by paper.
What is alpha radiation?
A radioactive isotope has a half-life of 10 minutes. If you start with 80 grams, how much will remain after 30 minutes?
What is 10 grams?
Burning wood is this type of change.
What is a chemical change?
A salad or a pizza is an example of this type of mixture.
What is heterogeneous?
This part of the atom has a positive charge.
What is a proton?
This subatomic particle has a negative charge.
What is an electron?
The splitting of a large nucleus into smaller nuclei is called this.
What is fission?
The charge of a beta particle.
What is -1?
You start with a radioactive substance that has a half-life of 6 hours. After 18 hours, only 5 grams remain. How much was there to begin with?
What is 40 g?
Matter that has only one type of atom is called this.
What is an element?
The smallest unit of a pure substance that cannot be broken down by chemical means.
What is an element?
The number of protons in an atom is also known as this, and it identifies the element.
What is the atomic number?
The sum of protons and neutrons in the nucleus equals this.
What is the mass number?
This type of nuclear reaction powers the sun.
What is fusion?
This type of radiation has no mass or charge but is very penetrating.
What is gamma radiation?
A substance has a half-life of 20 minutes. If you begin with 64 grams, how much remains after 60 minutes?
What is 8 grams?
A gas producing bubbles, a color change, and heat/light being released are all examples of this.
What is evidence of a chemical change?
Water (H₂O) is an example of this type of pure substance.
What is a compound?
Atoms with the same number of protons but different neutrons are called this.
What are isotopes?
The modern model of the atom shows electrons in regions called this.
What are electron clouds?
The time it takes for half of a radioactive isotope to decay is called this.
What is half-life?
This type of radiation can be blocked by aluminum foil.
What is beta radiation?
Two radioactive isotopes, A and B, start with the same mass. Isotope A has a half-life of 2 hours and isotope B has a half-life of 8 hours. After 8 hours, which isotope has more remaining, and why?
Isotope B has more remaining (because its half-life is longer, so it decays more slowly).
A substance that can be physically separated into simpler substances is this.
What is a mixture?
Salt water, air, and brass are examples of this type of mixture.
What are homogeneous mixtures (solutions)?
The weighted average of all isotopes of an element is called this.
What is average atomic mass?
This scientist proposed that electrons move in set energy levels around the nucleus.
Who is Niels Bohr?
During this type of decay, a helium nucleus is emitted.
What is alpha decay?
The process where an unstable nucleus emits particles or energy.
What is radioactive decay?
Carbon-14 has a half-life of about 5,730 years. A fossil bone is found with 25% of its original Carbon-14 remaining. About how old is the bone?
11460 years