Hacking the STAAR Category 1 (Periodic Table)

The table shows the chemical formulas for four substances. Which substances have the same number of carbon atoms?

• Substances 1 and 2

• Substances 2, 3, and 4

• Substances 2 and 3 only

• Substances 1 and 3

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

• H₃PO₄

• H₂SO₄

• HClO₃

• H₂O

Tags

NGSS.MS-PS1-1

Which statements correctly compare metals and nonmetals?

• Metals tend to be good conductors of thermal energy. Nonmetals tend to be good insulators of thermal energy.

• Metals are dull and brittle. Nonmetals are shiny and malleable.

• Metals are good insulators of electricity. Nonmetals tend to be good conductors of electricity.

• Metals cannot be stretched into thin wires. Nonmetals can be stretched into thin wires.

Tags

NGSS.MS-PS3-3

Which statement does NOT correctly compare silicon with another element?

• Silicon is a better conductor of electricity than sulfur.

• Silicon conducts electricity as well as copper does.

• Silicon is a solid at room temperature, but argon is a gas.

• Silicon is less malleable than silver.

The atomic number of krypton is 36. If the mass number of a krypton atom is 84, which table shows the number of subatomic particles inside and outside the nucleus of the krypton atom?

• Table A: Number of Particles Inside Nucleus (36), Number of Particles Outside Nucleus (36)

• Table B: Number of Particles Inside Nucleus (36), Number of Particles Outside Nucleus (48)

• Table C: Number of Particles Inside Nucleus (84), Number of Particles Outside Nucleus (36)

• Table D: Number of Particles Inside Nucleus (84), Number of Particles Outside Nucleus (48)

Tags

NGSS.MS-PS1-1

What is the difference between the number of electrons in an atom of selenium, Se, and the number of electrons in an atom of aluminum, Al?

What types of particles are found in the cloud surrounding the atom’s nucleus?

• Positively charged particles and negatively charged particles

• Negatively charged particles only

• Neutral particles and positively charged particles

• Positively charged particles only

Tags

NGSS.MS-PS1-1

Which pair of elements has reactivity that is similar to chlorine, Cl?

• Fluorine, F, and argon, Ar

• Fluorine, F, and iodine, I

• Sulfur, S, and bromine, Br

• Sulfur, S, and argon, Ar

Based on these drawings, which element is the least reactive?

• Neon, because it has two energy levels with eight electrons in the second level

• Chlorine, because it has three energy levels with seven electrons in the third level

• Gallium, because it has four energy levels with three electrons in the fourth level

• Tin, because it has five energy levels with four electrons in the fifth level

Tags

NGSS.MS-PS1-1